path: root/qpid/specs/amqp.0-9.xml

<?xml version = "1.0"?>

<!--
    EDITORS: (PH)   Pieter Hintjens <ph@imatix.com>
    (KvdR) Kim van der Riet <kim.vdriet@redhat.com>

    These editors have been assigned by the AMQP working group.
    Please do not edit/commit this file without consulting with
    one of the above editors.
    ========================================================

    TODOs
        - see TODO comments in the text
-->

<!--
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    ================
    (c) Copyright JPMorgan Chase Bank & Co., Cisco Systems, Inc., Envoy Technologies Inc.,
    iMatix Corporation, IONA\ufffd Technologies, Red Hat, Inc.,
    TWIST Process Innovations, and 29West Inc. 2006. All rights reserved.
    
    License
    =======
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    29West Inc. (collectively, the "Authors") each hereby grants to you a worldwide,
    perpetual, royalty-free, nontransferable, nonexclusive license to
    (i) copy, display, distribute and implement the Advanced Messaging Queue Protocol
    ("AMQP") Specification and (ii) the Licensed Claims that are held by
    the Authors, all for the purpose of implementing the Advanced Messaging
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    Messaging Queue Protocol Specification. For purposes of this definition,
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    Trademarks
    ==========
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    Octagon Symbol are trademarks of JPMorgan Chase & Co.
    
    IMATIX and the iMatix logo are trademarks of iMatix Corporation sprl.
    
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    Other company, product, or service names may be trademarks or service
    marks of others.
    
    Links to full AMQP specification:
    =================================
    http://www.envoytech.org/spec/amq/
    http://www.iona.com/opensource/amqp/
    http://www.redhat.com/solutions/specifications/amqp/
    http://www.twiststandards.org/tiki-index.php?page=AMQ
    http://www.imatix.com/amqp
-->

<!--
    <!DOCTYPE amqp SYSTEM "amqp.dtd">
-->

<!-- XML Notes

    We use entities to indicate repetition; attributes to indicate properties.

    We use the 'name' attribute as an identifier, usually within the context
    of the surrounding entities.

    We use spaces to seperate words in names, so that we can print names in
    their natural form depending on the context - underlines for source code,
    hyphens for written text, etc.

    We do not enforce any particular validation mechanism but we support all
    mechanisms.  The protocol definition conforms to a formal grammar that is
    published seperately in several technologies.

 -->

<amqp major = "0" minor = "9" port = "5672" comment = "AMQ Protocol version 0-9">
  <!--
      ======================================================
      ==       CONSTANTS
      ======================================================
  -->
  <!-- Frame types -->
  <constant name = "frame-method"     value = "1" />
  <constant name = "frame-header"     value = "2" />
  <constant name = "frame-body"       value = "3" />
  <constant name = "frame-oob-method" value = "4" />
  <constant name = "frame-oob-header" value = "5" />
  <constant name = "frame-oob-body"   value = "6" />
  <constant name = "frame-trace"      value = "7" />
  <constant name = "frame-heartbeat"  value = "8" />

  <!-- Protocol constants -->
  <constant name = "frame-min-size"   value = "4096" />
  <constant name = "frame-end"        value = "206" />

  <!-- Reply codes -->
  <constant name = "reply-success" value = "200">
    <doc>
      Indicates that the method completed successfully. This reply code is
      reserved for future use - the current protocol design does not use positive
      confirmation and reply codes are sent only in case of an error.
    </doc>
  </constant>

  <constant name = "not-delivered" value = "310" class = "soft-error">
    <doc>
      The client asked for a specific message that is no longer available.
      The message was delivered to another client, or was purged from the queue
      for some other reason.
    </doc>
  </constant>

  <constant name = "content-too-large" value = "311" class = "soft-error">
    <doc>
      The client attempted to transfer content larger than the server could accept
      at the present time. The client may retry at a later time.
    </doc>
  </constant>

  <constant name = "no-route" value = "312" class = "soft-error">
    <doc>
      When the exchange cannot route the result of a .Publish, most likely due
      to an invalid routing key. Only when the mandatory flag is set.
    </doc>
  </constant>

  <constant name = "no-consumers" value = "313" class = "soft-error">
    <doc>
      When the exchange cannot deliver to a consumer when the immediate flag is
      set. As a result of pending data on the queue or the absence of any
      consumers of the queue.
    </doc>
  </constant>

  <constant name = "connection-forced" value = "320" class = "hard-error">
    <doc>
      An operator intervened to close the connection for some reason. The client
      may retry at some later date.
    </doc>
  </constant>

  <constant name = "invalid-path" value = "402" class = "hard-error">
    <doc>
      The client tried to work with an unknown virtual host.
    </doc>
  </constant>

  <constant name = "access-refused" value = "403" class = "soft-error">
    <doc>
      The client attempted to work with a server entity to which it has no
      access due to security settings.
    </doc>
  </constant>

  <constant name = "not-found" value = "404" class = "soft-error">
    <doc>The client attempted to work with a server entity that does not exist.</doc>
  </constant>

  <constant name = "resource-locked" value = "405" class = "soft-error">
    <doc>
      The client attempted to work with a server entity to which it has no
      access because another client is working with it.
    </doc>
  </constant>

  <constant name = "precondition-failed" value = "406" class = "soft-error">
    <doc>
      The client requested a method that was not allowed because some precondition
      failed.
    </doc>
  </constant>

  <constant name = "frame-error" value = "501" class = "hard-error">
    <doc>
      The client sent a malformed frame that the server could not decode. This
      strongly implies a programming error in the client.
    </doc>
  </constant>

  <constant name = "syntax-error" value = "502" class = "hard-error">
    <doc>
      The client sent a frame that contained illegal values for one or more
      fields. This strongly implies a programming error in the client.
    </doc>
  </constant>

  <constant name = "command-invalid" value = "503" class = "hard-error">
    <doc>
      The client sent an invalid sequence of frames, attempting to perform an
      operation that was considered invalid by the server. This usually implies
      a programming error in the client.
    </doc>
  </constant>

  <constant name = "channel-error" value = "504" class = "hard-error">
    <doc>
      The client attempted to work with a channel that had not been correctly
      opened. This most likely indicates a fault in the client layer.
    </doc>
  </constant>

  <constant name = "resource-error" value = "506" class = "hard-error">
    <doc>
      The server could not complete the method because it lacked sufficient
      resources. This may be due to the client creating too many of some type
      of entity.
    </doc>
  </constant>

  <constant name = "not-allowed" value = "530" class = "hard-error">
    <doc>
      The client tried to work with some entity in a manner that is prohibited
      by the server, due to security settings or by some other criteria.
    </doc>
  </constant>

  <constant name = "not-implemented" value = "540" class = "hard-error">
    <doc>
      The client tried to use functionality that is not implemented in the
      server.
    </doc>
  </constant>

  <constant name = "internal-error" value = "541" class = "hard-error">
    <doc>
      The server could not complete the method because of an internal error.
      The server may require intervention by an operator in order to resume
      normal operations.
    </doc>
  </constant>

  <!--
      ======================================================
      ==       DOMAIN TYPES
      ======================================================
  -->

  <domain name = "access-ticket" type = "short" label = "access ticket granted by server">
    <doc>
      An access ticket granted by the server for a certain set of access rights
      within a specific realm. Access tickets are valid within the channel where
      they were created, and expire when the channel closes.
    </doc>
    <assert check = "ne" value = "0" />
  </domain>

  <domain name = "class-id" type = "short" />

  <domain name = "consumer-tag" type = "shortstr" label = "consumer tag">
    <doc>
      Identifier for the consumer, valid within the current connection.
    </doc>
  </domain>

  <domain name = "delivery-tag" type = "longlong" label = "server-assigned delivery tag">
    <doc>
      The server-assigned and channel-specific delivery tag
    </doc>
    <rule name = "channel-local">
      <doc>
        The delivery tag is valid only within the channel from which the message was
        received. I.e. a client MUST NOT receive a message on one channel and then
        acknowledge it on another.
      </doc>
    </rule>
    <rule name = "non-zero">
      <doc>
        The server MUST NOT use a zero value for delivery tags. Zero is reserved
        for client use, meaning "all messages so far received".
      </doc>
    </rule>
  </domain>

  <domain name = "exchange-name" type = "shortstr" label = "exchange name">
    <doc>
      The exchange name is a client-selected string that identifies the exchange for publish
      methods. Exchange names may consist of any mixture of digits, letters, and underscores.
      Exchange names are scoped by the virtual host.
    </doc>
    <assert check = "length" value = "127" />
  </domain>

  <domain name = "known-hosts" type = "shortstr" label = "list of known hosts">
    <doc>
      Specifies the list of equivalent or alternative hosts that the server knows about,
      which will normally include the current server itself. Clients can cache this
      information and use it when reconnecting to a server after a failure.  This field
      may be empty.
    </doc>
  </domain>

  <domain name = "method-id" type = "short" />

  <domain name = "no-ack" type = "bit" label = "no acknowledgement needed">
    <doc>
      If this field is set the server does not expect acknowledgements for
      messages. That is, when a message is delivered to the client the server
      automatically and silently acknowledges it on behalf of the client. This
      functionality increases performance but at the cost of reliability.
      Messages can get lost if a client dies before it can deliver them to the
      application.
    </doc>
  </domain>

  <domain name = "no-local" type = "bit" label = "do not deliver own messages">
    <doc>
      If the no-local field is set the server will not send messages to the connection that
      published them.
    </doc>
  </domain>

  <domain name = "path" type = "shortstr">
    <doc>
      Must start with a slash "/" and continue with path names separated by slashes. A path
      name consists of any combination of at least one of [A-Za-z0-9] plus zero or more of
      [.-_+!=:].
    </doc>

    <assert check = "notnull" />
    <assert check = "syntax" rule = "path" />
    <assert check = "length" value = "127" />
  </domain>

  <domain name = "peer-properties" type = "table">
    <doc>
      This string provides a set of peer properties, used for identification, debugging, and
      general information.
    </doc>
  </domain>

  <domain name = "queue-name" type = "shortstr" label = "queue name">
    <doc>
      The queue name identifies the queue within the vhost. Queue names may consist of any
      mixture of digits, letters, and underscores.
    </doc>
    <assert check = "length" value = "127" />
  </domain>

  <domain name = "redelivered" type = "bit" label = "message is being redelivered">
    <doc>
      This indicates that the message has been previously delivered to this or
      another client.
    </doc>
    <rule name = "implementation">
      <doc>
        The server SHOULD try to signal redelivered messages when it can. When
        redelivering a message that was not successfully acknowledged, the server
        SHOULD deliver it to the original client if possible.
      </doc>
      <doc type = "scenario">
        Create a shared queue and publish a message to the queue.  Consume the
        message using explicit acknowledgements, but do not acknowledge the
        message.  Close the connection, reconnect, and consume from the queue
        again.  The message should arrive with the redelivered flag set.
      </doc>
    </rule>
    <rule name = "hinting">
      <doc>
        The client MUST NOT rely on the redelivered field but should take it as a
        hint that the message may already have been processed. A fully robust
        client must be able to track duplicate received messages on non-transacted,
        and locally-transacted channels.
      </doc>
    </rule>
  </domain>

  <domain name = "reply-code" type = "short" label = "reply code from server">
    <doc>
      The reply code. The AMQ reply codes are defined as constants at the start
      of this formal specification.
    </doc>
    <assert check = "notnull" />
  </domain>

  <domain name = "reply-text" type = "shortstr" label = "localised reply text">
    <doc>
      The localised reply text. This text can be logged as an aid to resolving
      issues.
    </doc>
    <assert check = "notnull" />
  </domain>

  <domain name = "channel-id" type = "longstr" label = "unique identifier for a channel" />

  <!-- Domains for the message class -->
  <domain name = "duration" type = "longlong" label = "duration in milliseconds" />
  <domain name = "offset" type = "longlong" label = "offset into a message body" />
  <domain name = "reference" type = "longstr" label = "pointer to a message body" />
  <domain name = "destination" type = "shortstr" label = "destination for a message">
    <doc>
      Specifies the destination to which the message is to be
      transferred. The destination can be empty, meaning the
      default exchange or consumer.
    </doc>
  </domain>
  <domain name = "reject-code" type = "short" label = "reject code for transfer">
    <rule name = "01">
      <doc>
        The reject code must be one of 0 (generic) or 1 (immediate
        delivery was attempted but failed).
      </doc>
    </rule>
  </domain>
  <domain name = "reject-text" type = "shortstr" label = "informational text for message reject"/>
  <domain name = "security-token" type = "longstr" label = "security token">
    <doc>
      Used for authentication, replay prevention, and encrypted bodies.
    </doc>
  </domain>

  <!-- Elementary domains -->
  <domain name = "bit"        type = "bit"       label = "single bit" />
  <domain name = "octet"      type = "octet"     label = "single octet" />
  <domain name = "short"      type = "short"     label = "16-bit integer" />
  <domain name = "long"       type = "long"      label = "32-bit integer" />
  <domain name = "longlong"   type = "longlong"  label = "64-bit integer" />
  <domain name = "shortstr"   type = "shortstr"  label = "short string" />
  <domain name = "longstr"    type = "longstr"   label = "long string" />
  <domain name = "timestamp"  type = "timestamp" label = "64-bit timestamp" />
  <domain name = "table"      type = "table"     label = "field table" />

  <!-- ==  CONNECTION  ======================================================= -->

  <!-- TODO 0.81 - the 'handler' attribute of methods needs to be reviewed, and if
       no current implementations use it, removed. /PH 2006/07/20
       -->

  <class name = "connection" handler = "connection" index = "10" label = "work with socket connections">
    <doc>
      The connection class provides methods for a client to establish a network connection to
      a server, and for both peers to operate the connection thereafter.
    </doc>

    <doc type = "grammar">
      connection          = open-connection *use-connection close-connection
      open-connection     = C:protocol-header
                            S:START C:START-OK
                            *challenge
                            S:TUNE C:TUNE-OK
                            C:OPEN S:OPEN-OK | S:REDIRECT
      challenge           = S:SECURE C:SECURE-OK
      use-connection      = *channel
      close-connection    = C:CLOSE S:CLOSE-OK
                          / S:CLOSE C:CLOSE-OK
    </doc>

    <chassis name = "server" implement = "MUST" />
    <chassis name = "client" implement = "MUST" />

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "start" synchronous = "1" index = "10" label = "start connection negotiation">
      <doc>
        This method starts the connection negotiation process by telling the client the
        protocol version that the server proposes, along with a list of security mechanisms
        which the client can use for authentication.
      </doc>

      <rule name = "protocol-name">
        <doc>
          If the server cannot support the protocol specified in the protocol header,
          it MUST close the socket connection without sending any response method.
        </doc>
        <doc type = "scenario">
          The client sends a protocol header containing an invalid protocol name.
          The server must respond by closing the connection.
        </doc>
      </rule>
      <rule name = "server-support">
        <doc>
          The server MUST provide a protocol version that is lower than or equal to
          that requested by the client in the protocol header.
        </doc>
        <doc type = "scenario">
          The client requests a protocol version that is higher than any valid
          implementation, e.g. 9.0.  The server must respond with a current
          protocol version, e.g. 1.0.
        </doc>
      </rule>
      <rule name = "client-support">
        <doc>
          If the client cannot handle the protocol version suggested by the server
          it MUST close the socket connection.
        </doc>
        <doc type = "scenario">
          The server sends a protocol version that is lower than any valid
          implementation, e.g. 0.1.  The client must respond by closing the
          connection.
        </doc>
      </rule>

      <chassis name = "client" implement = "MUST" />
      <response name = "start-ok" />

      <field name = "version-major" domain = "octet" label = "protocol major version">
        <doc>
          The protocol version, major component, as transmitted in the AMQP protocol
          header. This, combined with the protocol minor component fully describe the
          protocol version, which is written in the format major-minor. Hence, with
          major=1, minor=3, the protocol version would be "1-3".
        </doc>
      </field>

      <field name = "version-minor" domain = "octet" label = "protocol minor version">
        <doc>
          The protocol version, minor component, as transmitted in the AMQP protocol
          header. This, combined with the protocol major component fully describe the
          protocol version, which is written in the format major-minor. Hence, with
          major=1, minor=3, the protocol version would be "1-3".
        </doc>
      </field>

      <field name = "server-properties" domain = "peer-properties" label = "server properties">
        <rule name = "required-fields">
          <doc>
            The properties SHOULD contain at least these fields: "host", specifying the
            server host name or address, "product", giving the name of the server product,
            "version", giving the name of the server version, "platform", giving the name
            of the operating system, "copyright", if appropriate, and "information", giving
            other general information.
          </doc>
          <doc type = "scenario">
            Client connects to server and inspects the server properties. It checks for
            the presence of the required fields.
          </doc>
        </rule>
      </field>

      <field name = "mechanisms" domain = "longstr" label = "available security mechanisms">
        <doc>
          A list of the security mechanisms that the server supports, delimited by spaces.
        </doc>
        <assert check = "notnull" />
      </field>

      <field name = "locales" domain = "longstr" label = "available message locales">
        <doc>
          A list of the message locales that the server supports, delimited by spaces. The
          locale defines the language in which the server will send reply texts.
        </doc>
        <rule name = "required-support">
          <doc>
            The server MUST support at least the en_US locale.
          </doc>
          <doc type = "scenario">
            Client connects to server and inspects the locales field. It checks for
            the presence of the required locale(s).
          </doc>
        </rule>
        <assert check = "notnull" />
      </field>
    </method>

    <method name = "start-ok" synchronous = "1" index = "11"
      label = "select security mechanism and locale">
      <doc>
        This method selects a SASL security mechanism.
      </doc>

      <chassis name = "server" implement = "MUST" />

      <field name = "client-properties" domain = "peer-properties" label = "client properties">
        <rule name = "required-fields">
          <!-- This rule is not testable from the client side -->
          <doc>
            The properties SHOULD contain at least these fields: "product", giving the name
            of the client product, "version", giving the name of the client version, "platform",
            giving the name of the operating system, "copyright", if appropriate, and
            "information", giving other general information.
          </doc>
        </rule>
      </field>

      <field name = "mechanism" domain = "shortstr" label = "selected security mechanism">
        <doc>
          A single security mechanisms selected by the client, which must be one of those
          specified by the server.
        </doc>
        <rule name = "security">
          <doc>
            The client SHOULD authenticate using the highest-level security profile it
            can handle from the list provided by the server.
          </doc>
        </rule>
        <rule name = "validity">
          <doc>
            If the mechanism field does not contain one of the security mechanisms
            proposed by the server in the Start method, the server MUST close the
            connection without sending any further data.
          </doc>
          <doc type = "scenario">
            Client connects to server and sends an invalid security mechanism. The
            server must respond by closing the connection (a socket close, with no
            connection close negotiation).
          </doc>
        </rule>
        <assert check = "notnull" />
      </field>

      <field name = "response" domain = "longstr" label = "security response data">
        <doc>
          A block of opaque data passed to the security mechanism. The contents of this
          data are defined by the SASL security mechanism.
        </doc>
        <assert check = "notnull" />
      </field>

      <field name = "locale" domain = "shortstr" label = "selected message locale">
        <doc>
          A single message locale selected by the client, which must be one of those
          specified by the server.
        </doc>
        <assert check = "notnull" />
      </field>
    </method>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "secure" synchronous = "1" index = "20" label = "security mechanism challenge">
      <doc>
        The SASL protocol works by exchanging challenges and responses until both peers have
        received sufficient information to authenticate each other. This method challenges
        the client to provide more information.
      </doc>

      <chassis name = "client" implement = "MUST" />
      <response name = "secure-ok" />

      <field name = "challenge" domain = "longstr" label = "security challenge data">
        <doc>
          Challenge information, a block of opaque binary data passed to the security
          mechanism.
        </doc>
      </field>
    </method>

    <method name = "secure-ok" synchronous = "1" index = "21" label = "security mechanism response">
      <doc>
        This method attempts to authenticate, passing a block of SASL data for the security
        mechanism at the server side.
      </doc>

      <chassis name = "server" implement = "MUST" />

      <field name = "response" domain = "longstr" label = "security response data">
        <doc>
          A block of opaque data passed to the security mechanism. The contents of this
          data are defined by the SASL security mechanism.
        </doc>
        <assert check = "notnull" />
      </field>
    </method>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "tune" synchronous = "1" index = "30"
      label = "propose connection tuning parameters">
      <doc>
        This method proposes a set of connection configuration values to the client. The
        client can accept and/or adjust these.
      </doc>

      <chassis name = "client" implement = "MUST" />

      <response name = "tune-ok" />

      <field name = "channel-max" domain = "short" label = "proposed maximum channels">
        <doc>
          The maximum total number of channels that the server allows per connection. Zero
          means that the server does not impose a fixed limit, but the number of allowed
          channels may be limited by available server resources.
        </doc>
      </field>

      <field name = "frame-max" domain = "long" label = "proposed maximum frame size">
        <doc>
          The largest frame size that the server proposes for the connection. The client
          can negotiate a lower value. Zero means that the server does not impose any
          specific limit but may reject very large frames if it cannot allocate resources
          for them.
        </doc>
        <rule name = "minimum">
          <doc>
            Until the frame-max has been negotiated, both peers MUST accept frames of up
            to frame-min-size octets large, and the minimum negotiated value for frame-max
            is also frame-min-size.
          </doc>
          <doc type = "scenario">
            Client connects to server and sends a large properties field, creating a frame
            of frame-min-size octets.  The server must accept this frame.
          </doc>
        </rule>
      </field>

      <field name = "heartbeat" domain = "short" label = "desired heartbeat delay">
        <!-- TODO 0.82 - the heartbeat negotiation mechanism was changed during
             implementation because the model documented here does not actually
             work properly.  The best model we found is that the server proposes
             a heartbeat value to the client; the client can reply with zero, meaning
             'do not use heartbeats (as documented here), or can propose its own
             heartbeat value, which the server should then accept.  This is different
             from the model here which is disconnected - e.g. each side requests a
             heartbeat independently.  Basically a connection is heartbeated in
             both ways, or not at all, depending on whether both peers support
             heartbeating or not, and the heartbeat value should itself be chosen
             by the client so that remote links can get a higher value.  Also, the
             actual heartbeat mechanism needs documentation, and is as follows: so
             long as there is activity on a connection - in or out - both peers
             assume the connection is active.  When there is no activity, each peer
             must send heartbeat frames.  When no heartbeat frame is received after
             N cycles (where N is at least 2), the connection can be considered to
             have died. /PH 2006/07/19
             -->
        <doc>
          The delay, in seconds, of the connection heartbeat that the server wants.
          Zero means the server does not want a heartbeat.
        </doc>
      </field>
    </method>

    <method name = "tune-ok" synchronous = "1" index = "31"
      label = "negotiate connection tuning parameters">
      <doc>
        This method sends the client's connection tuning parameters to the server.
        Certain fields are negotiated, others provide capability information.
      </doc>

      <chassis name = "server" implement = "MUST" />

      <field name = "channel-max" domain = "short" label = "negotiated maximum channels">
        <doc>
          The maximum total number of channels that the client will use per connection.
        </doc>
        <rule name = "upper-limit">
          <doc>
            If the client specifies a channel max that is higher than the value provided
            by the server, the server MUST close the connection without attempting a
            negotiated close.  The server may report the error in some fashion to assist
            implementors.
          </doc>
        </rule>
        <assert check = "notnull" />
        <assert check = "le" method = "tune" field = "channel-max" />
      </field>

      <field name = "frame-max" domain = "long" label = "negotiated maximum frame size">
        <doc>
          The largest frame size that the client and server will use for the connection.
          Zero means that the client does not impose any specific limit but may reject
          very large frames if it cannot allocate resources for them. Note that the
          frame-max limit applies principally to content frames, where large contents can
          be broken into frames of arbitrary size.
        </doc>
        <rule name = "minimum">
          <doc>
            Until the frame-max has been negotiated, both peers MUST accept frames of up
            to frame-min-size octets large, and the minimum negotiated value for frame-max
            is also frame-min-size.
          </doc>
        </rule>
        <rule name = "upper-limit">
          <doc>
            If the client specifies a frame max that is higher than the value provided
            by the server, the server MUST close the connection without attempting a
            negotiated close. The server may report the error in some fashion to assist
            implementors.
          </doc>
        </rule>
      </field>

      <field name = "heartbeat" domain = "short" label = "desired heartbeat delay">
        <doc>
          The delay, in seconds, of the connection heartbeat that the client wants. Zero
          means the client does not want a heartbeat.
        </doc>
      </field>
    </method>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "open" synchronous = "1" index = "40" label = "open connection to virtual host">
      <doc>
        This method opens a connection to a virtual host, which is a collection of
        resources, and acts to separate multiple application domains within a server.
        The server may apply arbitrary limits per virtual host, such as the number
        of each type of entity that may be used, per connection and/or in total.
      </doc>

      <chassis name = "server" implement = "MUST" />
      <response name = "open-ok" />
      <response name = "redirect" />

      <field name = "virtual-host" domain = "path" label = "virtual host name">
        <!-- TODO 0.82 - the entire vhost model needs review. This concept was
             prompted by the HTTP vhost concept but does not fit very well into
             AMQP.  Currently we use the vhost as a "cluster identifier" which is
             inaccurate usage. /PH 2006/07/19
             -->
        <assert check = "regexp" value = "^[a-zA-Z0-9/-_]+$" />
        <doc>
          The name of the virtual host to work with.
        </doc>
        <rule name = "separation">
          <doc>
            If the server supports multiple virtual hosts, it MUST enforce a full
            separation of exchanges, queues, and all associated entities per virtual
            host. An application, connected to a specific virtual host, MUST NOT be able
            to access resources of another virtual host.
          </doc>
        </rule>
        <rule name = "security">
          <doc>
            The server SHOULD verify that the client has permission to access the
            specified virtual host.
          </doc>
        </rule>
      </field>

      <field name = "capabilities" domain = "shortstr" label = "required capabilities">
        <doc>
          The client can specify zero or more capability names, delimited by spaces.
          The server can use this string to how to process the client's connection
          request.
        </doc>
      </field>

      <field name = "insist" domain = "bit" label = "insist on connecting to server">
        <doc>
          In a configuration with multiple collaborating servers, the server may respond
          to a Connection.Open method with a Connection.Redirect. The insist option tells
          the server that the client is insisting on a connection to the specified server.
        </doc>
        <rule name = "behaviour">
          <doc>
            When the client uses the insist option, the server MUST NOT respond with a
            Connection.Redirect method.  If it cannot accept the client's connection
            request it should respond by closing the connection with a suitable reply
            code.
          </doc>
        </rule>
      </field>
    </method>

    <method name = "open-ok" synchronous = "1" index = "41" label = "signal that connection is ready">
      <doc>
        This method signals to the client that the connection is ready for use.
      </doc>
      <chassis name = "client" implement = "MUST" />
      <field name = "known-hosts" domain = "known-hosts" />
    </method>

    <method name = "redirect" synchronous = "1" index = "42" label = "redirects client to other server">
      <doc>
        This method redirects the client to another server, based on the requested virtual
        host and/or capabilities.
      </doc>
      <rule name = "usage">
        <doc>
          When getting the Connection.Redirect method, the client SHOULD reconnect to
          the host specified, and if that host is not present, to any of the hosts
          specified in the known-hosts list.
        </doc>
      </rule>
      <chassis name = "client" implement = "MUST" />
      <field name = "host" domain = "shortstr" label = "server to connect to">
        <doc>
          Specifies the server to connect to. This is an IP address or a DNS name,
          optionally followed by a colon and a port number. If no port number is
          specified, the client should use the default port number for the protocol.
        </doc>
        <assert check = "notnull" />
      </field>
      <field name = "known-hosts" domain = "known-hosts" />
    </method>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "close" synchronous = "1" index = "50" label = "request a connection close">
      <doc>
        This method indicates that the sender wants to close the connection. This may be
        due to internal conditions (e.g. a forced shut-down) or due to an error handling
        a specific method, i.e. an exception. When a close is due to an exception, the
        sender provides the class and method id of the method which caused the exception.
      </doc>
      <!-- TODO: the connection close mechanism needs to be reviewed from the ODF
           documentation and better expressed as rules here. /PH 2006/07/20
           -->
      <rule name = "stability">
        <doc>
          After sending this method any received method except the Close-OK method MUST
          be discarded.
        </doc>
      </rule>

      <chassis name = "client" implement = "MUST" />
      <chassis name = "server" implement = "MUST" />
      <response name = "close-ok" />

      <field name = "reply-code" domain = "reply-code" />
      <field name = "reply-text" domain = "reply-text" />

      <field name = "class-id" domain = "class-id" label = "failing method class">
        <doc>
          When the close is provoked by a method exception, this is the class of the
          method.
        </doc>
      </field>

      <field name = "method-id" domain = "method-id" label = "failing method ID">
        <doc>
          When the close is provoked by a method exception, this is the ID of the method.
        </doc>
      </field>
    </method>

    <method name = "close-ok" synchronous = "1" index = "51" label = "confirm a connection close">
      <doc>
        This method confirms a Connection.Close method and tells the recipient that it is
        safe to release resources for the connection and close the socket.
      </doc>
      <rule name = "reporting">
        <doc>
          A peer that detects a socket closure without having received a Close-Ok
          handshake method SHOULD log the error.
        </doc>
      </rule>
      <chassis name = "client" implement = "MUST" />
      <chassis name = "server" implement = "MUST" />
    </method>
  </class>

  <!-- ==  CHANNEL  ========================================================== -->

  <class name = "channel" handler = "channel" index = "20" label = "work with channels">
    <doc>
      The channel class provides methods for a client to establish a channel to a
      server and for both peers to operate the channel thereafter.
    </doc>

    <doc type = "grammar">
      channel             = open-channel *use-channel close-channel
      open-channel        = C:OPEN S:OPEN-OK
                          / C:RESUME S:OK
      use-channel         = C:FLOW S:FLOW-OK
                          / S:FLOW C:FLOW-OK
                          / S:PING C:OK
                          / C:PONG S:OK
                          / C:PING S:OK
                          / S:PONG C:OK
                          / functional-class
      close-channel       = C:CLOSE S:CLOSE-OK
                          / S:CLOSE C:CLOSE-OK
    </doc>

    <chassis name = "server" implement = "MUST" />
    <chassis name = "client" implement = "MUST" />

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "open" synchronous = "1" index = "10" label = "open a channel for use">
      <doc>
        This method opens a channel to the server.
      </doc>
      <rule name = "state" on-failure = "channel-error">
        <doc>
          The client MUST NOT use this method on an already-opened channel.
        </doc>
        <doc type = "scenario">
          Client opens a channel and then reopens the same channel.
        </doc>
      </rule>
      <chassis name = "server" implement = "MUST" />
      <response name = "open-ok" />
      <field name = "out-of-band" domain = "shortstr" label = "out-of-band settings">
        <doc>
          Configures out-of-band transfers on this channel. The syntax and meaning of this
          field will be formally defined at a later date.
        </doc>
        <assert check = "null" />
      </field>
    </method>

    <method name = "open-ok" synchronous = "1" index = "11" label = "signal that the channel is ready">
      <doc>
        This method signals to the client that the channel is ready for use.
      </doc>
      <chassis name = "client" implement = "MUST" />
      <field name = "channel-id" domain = "channel-id" />
    </method>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "flow" synchronous = "1" index = "20" label = "enable/disable flow from peer">
      <doc>
        This method asks the peer to pause or restart the flow of content data. This is a
        simple flow-control mechanism that a peer can use to avoid overflowing its queues or
        otherwise finding itself receiving more messages than it can process. Note that this
        method is not intended for window control. The peer that receives a disable flow
        method should finish sending the current content frame, if any, then pause.
      </doc>

      <rule name = "initial-state">
        <doc>
          When a new channel is opened, it is active (flow is active). Some applications
          assume that channels are inactive until started. To emulate this behaviour a
          client MAY open the channel, then pause it.
        </doc>
      </rule>

      <rule name = "bidirectional">
        <doc>
          When sending content frames, a peer SHOULD monitor the channel for incoming
          methods and respond to a Channel.Flow as rapidly as possible.
        </doc>
      </rule>

      <rule name = "throttling">
        <doc>
          A peer MAY use the Channel.Flow method to throttle incoming content data for
          internal reasons, for example, when exchanging data over a slower connection.
        </doc>
      </rule>

      <rule name = "expected-behaviour">
        <doc>
          The peer that requests a Channel.Flow method MAY disconnect and/or ban a peer
          that does not respect the request.  This is to prevent badly-behaved clients
          from overwhelming a broker.
        </doc>
      </rule>

      <chassis name = "server" implement = "MUST" />
      <chassis name = "client" implement = "MUST" />

      <response name = "flow-ok" />

      <field name = "active" domain = "bit" label = "start/stop content frames">
        <doc>
          If 1, the peer starts sending content frames. If 0, the peer stops sending
          content frames.
        </doc>
      </field>
    </method>

    <method name = "flow-ok" index = "21" label = "confirm a flow method">
      <doc>
        Confirms to the peer that a flow command was received and processed.
      </doc>
      <chassis name = "server" implement = "MUST" />
      <chassis name = "client" implement = "MUST" />
      <field name = "active" domain = "bit" label = "current flow setting">
        <doc>
          Confirms the setting of the processed flow method: 1 means the peer will start
          sending or continue to send content frames; 0 means it will not.
        </doc>
      </field>
    </method>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "close" synchronous = "1" index = "40" label = "request a channel close">
      <doc>
        This method indicates that the sender wants to close the channel. This may be due to
        internal conditions (e.g. a forced shut-down) or due to an error handling a specific
        method, i.e. an exception. When a close is due to an exception, the sender provides
        the class and method id of the method which caused the exception.
      </doc>

      <!-- TODO: the channel close behaviour needs to be reviewed from the ODF
           documentation and better expressed as rules here. /PH 2006/07/20
           -->
      <rule name = "stability">
        <doc>
          After sending this method any received method except the Close-OK method MUST
          be discarded.
        </doc>
      </rule>

      <chassis name = "client" implement = "MUST" />
      <chassis name = "server" implement = "MUST" />
      <response name = "close-ok" />

      <field name = "reply-code" domain = "reply-code" />
      <field name = "reply-text" domain = "reply-text" />

      <field name = "class-id" domain = "class-id" label = "failing method class">
        <doc>
          When the close is provoked by a method exception, this is the class of the
          method.
        </doc>
      </field>

      <field name = "method-id" domain = "method-id" label = "failing method ID">
        <doc>
          When the close is provoked by a method exception, this is the ID of the method.
        </doc>
      </field>
    </method>

    <method name = "close-ok" synchronous = "1" index = "41" label = "confirm a channel close">
      <doc>
        This method confirms a Channel.Close method and tells the recipient that it is safe
        to release resources for the channel.
      </doc>
      <rule name = "reporting">
        <doc>
          A peer that detects a socket closure without having received a Channel.Close-Ok
          handshake method SHOULD log the error.
        </doc>
      </rule>
      <chassis name = "client" implement = "MUST" />
      <chassis name = "server" implement = "MUST" />
    </method>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "resume" index = "50" label = "resume an interrupted channel">
      <doc>
        This method resume a previously interrupted channel.
      </doc>
      <response name = "ok" />
      <chassis name = "server" implement = "MAY" />
      <field name = "channel-id" domain = "channel-id" />
    </method>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "ping" index = "60" label = "[WORK IN PROGRESS] initiates a pong">
      <doc>
        [WORK IN PROGRESS] Request that the recipient issue a pong request.
      </doc>
      <response name = "ok" />
      <chassis name = "server" implement = "MUST" />
      <chassis name = "client" implement = "MUST" />
    </method>

    <method name = "pong" index = "70" label = "[WORK IN PROGRESS] issued after receiving a ping">
      <doc>
        [WORK IN PROGRESS] Issued after a ping request is received. Note that this is a
        request issued after receiving a ping, not a response to
        receiving a ping.
      </doc>
      <response name = "ok" />
      <chassis name = "server" implement = "MUST" />
      <chassis name = "client" implement = "MUST" />
    </method>

    <method name = "ok" index = "80" label = "[WORK IN PROGRESS] signals normal completion">
      <doc>
        [WORK IN PROGRESS] Signals normal completion of a method.
      </doc>
      <chassis name = "server" implement = "MUST" />
      <chassis name = "client" implement = "MUST" />
    </method>
  </class>

  <!-- ==  ACCESS  =========================================================== -->

  <!-- TODO 0.82 - this class must be implemented by two teams before we can
       consider it matured.
    -->

  <class name = "access" handler = "connection" index = "30" label = "work with access tickets">
    <doc>
      The protocol control access to server resources using access tickets. A
      client must explicitly request access tickets before doing work. An access
      ticket grants a client the right to use a specific set of resources -
      called a "realm" - in specific ways.
    </doc>

    <doc type = "grammar">
      access              = C:REQUEST S:REQUEST-OK
    </doc>

    <chassis name = "server" implement = "MUST" />
    <chassis name = "client" implement = "MUST" />

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "request" synchronous = "1" index = "10" label = "request an access ticket">
      <doc>
        This method requests an access ticket for an access realm. The server
        responds by granting the access ticket. If the client does not have
        access rights to the requested realm this causes a connection exception.
        Access tickets are a per-channel resource.
      </doc>

      <chassis name = "server" implement = "MUST" />
      <response name = "request-ok" />

      <field name = "realm" domain = "shortstr" label = "name of requested realm">
        <doc>
          Specifies the name of the realm to which the client is requesting access.
          The realm is a configured server-side object that collects a set of
          resources (exchanges, queues, etc.).  If the channel has already requested
          an access ticket onto this realm, the previous ticket is destroyed and a
          new ticket is created with the requested access rights, if allowed.
        </doc>
        <rule name = "validity" on-failure = "access-refused">
          <doc>
            The client MUST specify a realm that is known to the server.  The server
            makes an identical response for undefined realms as it does for realms
            that are defined but inaccessible to this client.
          </doc>
          <doc type = "scenario">
            Client specifies an undefined realm.
          </doc>
        </rule>
      </field>

      <field name = "exclusive" domain = "bit" label = "request exclusive access">
        <doc>
          Request exclusive access to the realm, meaning that this will be the only
          channel that uses the realm's resources.
        </doc>
        <rule name = "validity" on-failure = "access-refused">
          <doc>
            The client MAY NOT request exclusive access to a realm that has active
            access tickets, unless the same channel already had the only access
            ticket onto that realm.
          </doc>
          <doc type = "scenario">
            Client opens two channels and requests exclusive access to the same realm.
          </doc>
        </rule>
      </field>
      <field name = "passive" domain = "bit" label = "request passive access">
        <doc>
          Request message passive access to the specified access realm. Passive
          access lets a client get information about resources in the realm but
          not to make any changes to them.
        </doc>
      </field>
      <field name = "active" domain = "bit" label = "request active access">
        <doc>
          Request message active access to the specified access realm. Active access lets
          a client get create and delete resources in the realm.
        </doc>
      </field>
      <field name = "write" domain = "bit" label = "request write access">
        <doc>
          Request write access to the specified access realm. Write access lets a client
          publish messages to all exchanges in the realm.
        </doc>
      </field>
      <field name = "read" domain = "bit" label = "request read access">
        <doc>
          Request read access to the specified access realm. Read access lets a client
          consume messages from queues in the realm.
        </doc>
      </field>
    </method>

    <method name = "request-ok" synchronous = "1" index = "11" label = "grant access to server resources">
      <doc>
        This method provides the client with an access ticket. The access ticket is valid
        within the current channel and for the lifespan of the channel.
      </doc>
      <rule name = "per-channel" on-failure = "not-allowed">
        <doc>
          The client MUST NOT use access tickets except within the same channel as
          originally granted.
        </doc>
        <doc type = "scenario">
          Client opens two channels, requests a ticket on one channel, and then
          tries to use that ticket in a second channel.
        </doc>
      </rule>
      <chassis name = "client" implement = "MUST" />
      <field name = "ticket" domain = "access-ticket" />
    </method>
  </class>

  <!-- ==  EXCHANGE  ========================================================= -->

  <class name = "exchange" handler = "channel" index = "40" label = "work with exchanges">
    <doc>
      Exchanges match and distribute messages across queues. Exchanges can be configured in
      the server or created at runtime.
    </doc>

    <doc type = "grammar">
      exchange            = C:DECLARE  S:DECLARE-OK
                          / C:DELETE   S:DELETE-OK
    </doc>

    <chassis name = "server" implement = "MUST" />
    <chassis name = "client" implement = "MUST" />

    <rule name = "required-types">
      <doc>
        The server MUST implement these standard exchange types: fanout, direct.
      </doc>
      <doc type = "scenario">
        Client attempts to declare an exchange with each of these standard types.
      </doc>
    </rule>
    <rule name = "recommended-types">
      <doc>
        The server SHOULD implement these standard exchange types: topic, headers.
      </doc>
      <doc type = "scenario">
        Client attempts to declare an exchange with each of these standard types.
      </doc>
    </rule>
    <rule name = "required-instances">
      <doc>
        The server MUST, in each virtual host, pre-declare an exchange instance
        for each standard exchange type that it implements, where the name of the
        exchange instance, if defined, is "amq." followed by the exchange type name.
      </doc>
      <doc>
        The server MUST, in each virtual host, pre-declare at least two direct
        exchange instances: one named "amq.direct", the other with no public name
        that serves as a default  exchange for Publish methods.
      </doc>
      <doc type = "scenario">
        Client creates a temporary queue and attempts to bind to each required
        exchange instance ("amq.fanout", "amq.direct", "amq.topic", and "amq.headers"
        if those types are defined).
      </doc>
    </rule>
    <rule name = "default-exchange">
      <doc>
        The server MUST pre-declare a direct exchange with no public name to act as
        the default exchange for content Publish methods and for default queue bindings.
      </doc>
      <doc type = "scenario">
        Client checks that the default exchange is active by specifying a queue
        binding with no exchange name, and publishing a message with a suitable
        routing key but without specifying the exchange name, then ensuring that
        the message arrives in the queue correctly.
      </doc>
    </rule>
    <rule name = "default-access">
      <doc>
        The server MUST NOT allow clients to access the default exchange except
        by specifying an empty exchange name in the Queue.Bind and content Publish
        methods.
      </doc>
    </rule>
    <rule name = "extensions">
      <doc>
        The server MAY implement other exchange types as wanted.
      </doc>
    </rule>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "declare" synchronous = "1" index = "10" label = "verify exchange exists, create if needed">
      <doc>
        This method creates an exchange if it does not already exist, and if the exchange
        exists, verifies that it is of the correct and expected class.
      </doc>
      <rule name = "minimum">
        <doc>
          The server SHOULD support a minimum of 16 exchanges per virtual host and
          ideally, impose no limit except as defined by available resources.
        </doc>
        <doc type = "scenario">
          The client creates as many exchanges as it can until the server reports
          an error; the number of exchanges successfully created must be at least
          sixteen.
        </doc>
      </rule>

      <chassis name = "server" implement = "MUST" />
      <response name = "declare-ok" />

      <field name = "ticket" domain = "access-ticket">
        <doc>
          When a client defines a new exchange, this belongs to the access realm of the
          ticket used. All further work done with that exchange must be done with an
          access ticket for the same realm.
        </doc>
        <rule name = "validity" on-failure = "access-refused">
          <doc>
            The client MUST provide a valid access ticket giving "active" access to
            the realm in which the exchange exists or will be created, or "passive"
            access if the if-exists flag is set.
          </doc>
          <doc type = "scenario">
            Client creates access ticket with wrong access rights and attempts to use
            in this method.
          </doc>
        </rule>
      </field>

      <field name = "exchange" domain = "exchange-name">
        <rule name = "reserved" on-failure = "access-refused">
          <doc>
            Exchange names starting with "amq." are reserved for pre-declared and
            standardised exchanges. The client MUST NOT attempt to create an exchange
            starting with "amq.".
          </doc>
          <doc type = "scenario">
            TODO.
          </doc>
        </rule>
        <assert check = "regexp" value = "^[a-zA-Z0-9-_.:]+$" />
      </field>

      <field name = "type" domain = "shortstr" label = "exchange type">
        <doc>
          Each exchange belongs to one of a set of exchange types implemented by the
          server. The exchange types define the functionality of the exchange - i.e. how
          messages are routed through it. It is not valid or meaningful to attempt to
          change the type of an existing exchange.
        </doc>
        <rule name = "typed" on-failure = "not-allowed">
          <doc>
            Exchanges cannot be redeclared with different types.  The client MUST not
            attempt to redeclare an existing exchange with a different type than used
            in the original Exchange.Declare method.
          </doc>
          <doc type = "scenario">
            TODO.
          </doc>
        </rule>
        <rule name = "support" on-failure = "command-invalid">
          <doc>
            The client MUST NOT attempt to create an exchange with a type that the
            server does not support.
          </doc>
          <doc type = "scenario">
            TODO.
          </doc>
        </rule>
        <assert check = "regexp" value = "^[a-zA-Z0-9-_.:]+$" />
      </field>

      <field name = "passive" domain = "bit" label = "do not create exchange">
        <doc>
          If set, the server will not create the exchange. The client can use this to
          check whether an exchange exists without modifying the server state.
        </doc>
        <rule name = "not-found">
          <doc>
            If set, and the exchange does not already exist, the server MUST raise a
            channel exception with reply code 404 (not found).
          </doc>
          <doc type = "scenario">
            TODO.
          </doc>
        </rule>
      </field>

      <field name = "durable" domain = "bit" label = "request a durable exchange">
        <doc>
          If set when creating a new exchange, the exchange will be marked as durable.
          Durable exchanges remain active when a server restarts. Non-durable exchanges
          (transient exchanges) are purged if/when a server restarts.
        </doc>
        <rule name = "support">
          <doc>
            The server MUST support both durable and transient exchanges.
          </doc>
          <doc type = "scenario">
            TODO.
          </doc>
        </rule>
        <rule name = "sticky">
          <doc>
            The server MUST ignore the durable field if the exchange already exists.
          </doc>
          <doc type = "scenario">
            TODO.
          </doc>
        </rule>
      </field>

      <!-- TODO 0.82 - clarify how this works; there is no way to cancel a binding
           except by deleting a queue.
         -->
      <field name = "auto-delete" domain = "bit" label = "auto-delete when unused">
        <doc>
          If set, the exchange is deleted when all queues have finished using it.
        </doc>
        <rule name = "sticky">
          <doc>
            The server MUST ignore the auto-delete field if the exchange already
            exists.
          </doc>
          <doc type = "scenario">
            TODO.
          </doc>
        </rule>
      </field>

      <field name = "internal" domain = "bit" label = "create internal exchange">
        <doc>
          If set, the exchange may not be used directly by publishers, but only when bound
          to other exchanges. Internal exchanges are used to construct wiring that is not
          visible to applications.
        </doc>
      </field>

      <field name = "nowait" domain = "bit" label = "do not send reply method">
        <doc>
          If set, the server will not respond to the method. The client should not wait
          for a reply method. If the server could not complete the method it will raise a
          channel or connection exception.
        </doc>
      </field>

      <field name = "arguments" domain = "table" label = "arguments for declaration">
        <doc>
          A set of arguments for the declaration. The syntax and semantics of these
          arguments depends on the server implementation. This field is ignored if passive
          is 1.
        </doc>
      </field>
    </method>

    <method name = "declare-ok" synchronous = "1" index = "11" label = "confirm exchange declaration">
      <doc>
        This method confirms a Declare method and confirms the name of the exchange,
        essential for automatically-named exchanges.
      </doc>
      <chassis name = "client" implement = "MUST" />
    </method>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "delete" synchronous = "1" index = "20" label = "delete an exchange">
      <doc>
        This method deletes an exchange. When an exchange is deleted all queue bindings on
        the exchange are cancelled.
      </doc>

      <chassis name = "server" implement = "MUST" />
      <response name = "delete-ok" />

      <field name = "ticket" domain = "access-ticket">
        <rule name = "validity" on-failure = "access-refused">
          <doc>
            The client MUST provide a valid access ticket giving "active" access
            rights to the exchange's access realm.
          </doc>
          <doc type = "scenario">
            Client creates access ticket with wrong access rights and attempts to use
            in this method.
          </doc>
        </rule>
      </field>

      <field name = "exchange" domain = "exchange-name">
        <rule name = "exists" on-failure = "not-found">
          <doc>
            The client MUST NOT attempt to delete an exchange that does not exist.
          </doc>
        </rule>
        <assert check = "notnull" />
      </field>

      <!-- TODO 0.82 - discuss whether this option is useful or not.  I don't have
           any real use case for it. /PH 2006-07-23.
         -->
      <field name = "if-unused" domain = "bit" label = "delete only if unused">
        <doc>
          If set, the server will only delete the exchange if it has no queue bindings. If
          the exchange has queue bindings the server does not delete it but raises a
          channel exception instead.
        </doc>
      </field>

      <field name = "nowait" domain = "bit" label = "do not send a reply method">
        <doc>
          If set, the server will not respond to the method. The client should not wait
          for a reply method. If the server could not complete the method it will raise a
          channel or connection exception.
        </doc>
      </field>
    </method>

    <method name = "delete-ok" synchronous = "1" index = "21"
      label = "confirm deletion of an exchange">
      <doc>This method confirms the deletion of an exchange.</doc>
      <chassis name = "client" implement = "MUST" />
    </method>
  </class>

  <!-- ==  QUEUE  ============================================================ -->

  <class name = "queue" handler = "channel" index = "50" label = "work with queues">
    <doc>
      Queues store and forward messages. Queues can be configured in the server or created at
      runtime. Queues must be attached to at least one exchange in order to receive messages
      from publishers.
    </doc>

    <doc type = "grammar">
      queue               = C:DECLARE  S:DECLARE-OK
                          / C:BIND     S:BIND-OK
                          / C:PURGE    S:PURGE-OK
                          / C:DELETE   S:DELETE-OK
    </doc>

    <chassis name = "server" implement = "MUST" />
    <chassis name = "client" implement = "MUST" />

    <rule name = "any-content">
      <doc>
        A server MUST allow any content class to be sent to any queue, in any mix, and
        queue and deliver these content classes independently. Note that all methods
        that fetch content off queues are specific to a given content class.
      </doc>
      <doc type = "scenario">
        Client creates an exchange of each standard type and several queues that
        it binds to each exchange. It must then successfully send each of the standard
        content types to each of the available queues.
      </doc>
    </rule>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "declare" synchronous = "1" index = "10" label = "declare queue, create if needed">
      <doc>
        This method creates or checks a queue. When creating a new queue the client can
        specify various properties that control the durability of the queue and its
        contents, and the level of sharing for the queue.
      </doc>

      <rule name = "default-binding">
        <doc>
          The server MUST create a default binding for a newly-created queue to the
          default exchange, which is an exchange of type 'direct' and use the queue
          name as the routing key.
        </doc>
        <doc type = "scenario">
          Client creates a new queue, and then without explicitly binding it to an
          exchange, attempts to send a message through the default exchange binding,
          i.e. publish a message to the empty exchange, with the queue name as routing
          key.
        </doc>
      </rule>

      <!-- Rule test name: was "amq_queue_35" -->
      <rule name = "minimum-queues">
        <doc>
          The server SHOULD support a minimum of 256 queues per virtual host and ideally,
          impose no limit except as defined by available resources.
        </doc>
        <doc type = "scenario">
          Client attempts to create as many queues as it can until the server reports
          an error.  The resulting count must at least be 256.
        </doc>
      </rule>

      <chassis name = "server" implement = "MUST" />
      <response name = "declare-ok" />

      <field name = "ticket" domain = "access-ticket">
        <doc>
          When a client defines a new queue, this belongs to the access realm of the
          ticket used. All further work done with that queue must be done with an access
          ticket for the same realm.
        </doc>
        <rule name = "validity" on-failure = "access-refused">
          <doc>
            The client MUST provide a valid access ticket giving "active" access to
            the realm in which the queue exists or will be created.
          </doc>
          <doc type = "scenario">
            Client creates access ticket with wrong access rights and attempts to use
            in this method.
          </doc>
        </rule>
      </field>

      <field name = "queue" domain = "queue-name">
        <rule name = "default-name">
          <doc>
            The queue name MAY be empty, in which case the server MUST create a new
            queue with a unique generated name and return this to the client in the
            Declare-Ok method.
          </doc>
          <doc type = "scenario">
            Client attempts to create several queues with an empty name. The client then
            verifies that the server-assigned names are unique and different.
          </doc>
        </rule>
        <rule name = "reserved-prefix" on-failure = "not-allowed">
          <doc>
            Queue names starting with "amq." are reserved for pre-declared and
            standardised server queues. A client MAY NOT attempt to declare a queue with a
            name  that starts with "amq." and the passive option set to zero.
          </doc>
          <doc type = "scenario">
            A client attempts to create a queue with a name starting with "amq." and with
            the passive option set to zero.
          </doc>
        </rule>
        <assert check = "regexp" value = "^[a-zA-Z0-9-_.:]*$" />
      </field>

      <field name = "passive" domain = "bit" label = "do not create queue">
        <doc>
          If set, the server will not create the queue. This field allows the client
          to assert the presence of a queue without modifying the server state.
        </doc>
        <rule name = "passive" on-failure = "not-found">
          <doc>
            The client MAY ask the server to assert that a queue exists without
            creating the queue if not.  If the queue does not exist, the server
            treats this as a failure.
          </doc>
          <doc type = "scenario">
            Client declares an existing queue with the passive option and expects
            the server to respond with a declare-ok. Client then attempts to declare
            a non-existent queue with the passive option, and the server must close
            the channel with the correct reply-code.
          </doc>
        </rule>
      </field>

      <field name = "durable" domain = "bit" label = "request a durable queue">
        <doc>
          If set when creating a new queue, the queue will be marked as durable. Durable
          queues remain active when a server restarts. Non-durable queues (transient
          queues) are purged if/when a server restarts. Note that durable queues do not
          necessarily hold persistent messages, although it does not make sense to send
          persistent messages to a transient queue.
        </doc>
        <!-- Rule test name: was "amq_queue_03" -->
        <rule name = "persistence">
          <doc>The server MUST recreate the durable queue after a restart.</doc>

          <!-- TODO: use 'client does something' rather than 'a client does something'. -->
          <doc type = "scenario">
            A client creates a durable queue. The server is then restarted. The client
            then attempts to send a message to the queue. The message should be successfully
            delivered.
          </doc>
        </rule>
        <!-- Rule test name: was "amq_queue_36" -->
        <rule name = "types">
          <doc>The server MUST support both durable and transient queues.</doc>
          <doc type = "scenario">
            A client creates two named queues, one durable and one transient.
          </doc>
        </rule>
        <!-- Rule test name: was "amq_queue_37" -->    
        <rule name = "pre-existence">
          <doc>The server MUST ignore the durable field if the queue already exists.</doc>
          <doc type = "scenario">
            A client creates two named queues, one durable and one transient. The client
            then attempts to declare the two queues using the same names again, but reversing
            the value of the durable flag in each case. Verify that the queues still exist
            with the original durable flag values.
            <!-- TODO: but how? -->
          </doc>
        </rule>
      </field>

      <field name = "exclusive" domain = "bit" label = "request an exclusive queue">
        <doc>
          Exclusive queues may only be consumed from by the current connection. Setting
          the 'exclusive' flag always implies 'auto-delete'.
        </doc>

        <!-- Rule test name: was "amq_queue_38" -->
        <rule name = "types">
          <doc>
            The server MUST support both exclusive (private) and non-exclusive (shared)
            queues.
          </doc>
          <doc type = "scenario">
            A client creates two named queues, one exclusive and one non-exclusive.
          </doc>
        </rule>

        <!-- Rule test name: was "amq_queue_04" -->    
        <rule name = "02" on-failure = "channel-error">
          <doc>
            The client MAY NOT attempt to declare any existing and exclusive queue
            on multiple connections.
          </doc>
          <doc type = "scenario">
            A client declares an exclusive named queue. A second client on a different
            connection attempts to declare a queue of the same name.
          </doc>
        </rule>
      </field>

      <field name = "auto-delete" domain = "bit" label = "auto-delete queue when unused">
        <doc>
          If set, the queue is deleted when all consumers have finished using it. Last
          consumer can be cancelled either explicitly or because its channel is closed. If
          there was no consumer ever on the queue, it won't be deleted.
        </doc>

        <!-- Rule test name: was "amq_queue_31" -->
        <rule name = "pre-existence">
          <doc>
            The server MUST ignore the auto-delete field if the queue already exists.
          </doc>
          <doc type = "scenario">
            A client creates two named queues, one as auto-delete and one explicit-delete.
            The client then attempts to declare the two queues using the same names again,
            but reversing the value of the auto-delete field in each case. Verify that the
            queues still exist with the original auto-delete flag values.
            <!-- TODO: but how? -->
          </doc>
        </rule>
      </field>

      <field name = "nowait" domain = "bit" label = "do not send a reply method">
        <doc>
          If set, the server will not respond to the method. The client should not wait
          for a reply method. If the server could not complete the method it will raise a
          channel or connection exception.
        </doc>
      </field>

      <field name = "arguments" domain = "table" label = "arguments for declaration">
        <doc>
          A set of arguments for the declaration. The syntax and semantics of these
          arguments depends on the server implementation. This field is ignored if passive
          is 1.
        </doc>
      </field>
    </method>

    <method name = "declare-ok" synchronous = "1" index = "11" label = "confirms a queue definition">
      <doc>
        This method confirms a Declare method and confirms the name of the queue, essential
        for automatically-named queues.
      </doc>
      
      <chassis name = "client" implement = "MUST" />
      
      <field name = "queue" domain = "queue-name">
        <doc>
          Reports the name of the queue. If the server generated a queue name, this field
          contains that name.
        </doc>
        <assert check = "notnull" />
      </field>

      <field name = "message-count" domain = "long" label = "number of messages in queue">
        <doc>
          Reports the number of messages in the queue, which will be zero for
          newly-created queues.
        </doc>
      </field>
      
      <field name = "consumer-count" domain = "long" label = "number of consumers">
        <doc>
          Reports the number of active consumers for the queue. Note that consumers can
          suspend activity (Channel.Flow) in which case they do not appear in this count.
        </doc>
      </field>
    </method>
    
    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->
    
    <method name = "bind" synchronous = "1" index = "20" label = "bind queue to an exchange">
      <doc>
        This method binds a queue to an exchange. Until a queue is bound it will not receive
        any messages. In a classic messaging model, store-and-forward queues are bound to a
        direct exchange and subscription queues are bound to a topic exchange.
      </doc>

      <!-- Rule test name: was "amq_queue_25" -->
      <rule name = "duplicates">
        <doc>
          A server MUST allow ignore duplicate bindings - that is, two or more bind
          methods for a specific queue, with identical arguments - without treating these
          as an error.
        </doc>
        <doc type = "scenario">
          A client binds a named queue to an exchange. The client then repeats the bind
          (with identical arguments).
        </doc>
      </rule>

      <!-- Rule test name: was "amq_queue_39" -->
      <rule name = "failure">
        <!--
        TODO: Find correct on-failure code. The on-failure code returned should depend on why the bind
        failed. Assuming that failures owing to bad parameters are covered in the rules relating
        to those parameters, the only remaining reason for a failure would be the lack of
        server resorces or some internal error - such as too many queues open. Would these
        cases qualify as "resource error" 506 or "internal error" 541?
        -->
        <doc>If a bind fails, the server MUST raise a connection exception.</doc>
        <doc type = "scenario">
          TODO
        </doc>
      </rule>

      <!-- Rule test name: was "amq_queue_12" -->
      <rule name = "transient-exchange" on-failure = "not-allowed">
        <doc>
          The server MUST NOT allow a durable queue to bind to a transient exchange.
        </doc>
        <doc type = "scenario">
          A client creates a transient exchange. The client then declares a named durable
          queue and then attempts to bind the transient exchange to the durable queue.
        </doc>
      </rule>

      <!-- Rule test name: was "amq_queue_13" -->
      <rule name = "durable-exchange">
        <doc>
          Bindings for durable queues are automatically durable and the server SHOULD
          restore such bindings after a server restart.
        </doc>
        <doc type = "scenario">
          A server creates a named durable queue and binds it to a durable exchange. The
          server is restarted. The client then attempts to use the queue/exchange combination.
        </doc>
      </rule>

      <!-- Rule test name: was "amq_queue_17" -->
      <rule name = "internal-exchange">
        <doc>
          If the client attempts to bind to an exchange that was declared as internal, the server
          MUST raise a connection exception with reply code 530 (not allowed).
        </doc>
        <doc type = "scenario">
          A client attempts to bind a named queue to an internal exchange.
        </doc>
      </rule>

      <!-- Rule test name: was "amq_queue_40" -->
      <rule name = "binding-count">
        <doc>
          The server SHOULD support at least 4 bindings per queue, and ideally, impose no
          limit except as defined by available resources.
        </doc>
        <doc type = "scenario">
          A client creates a named queue and attempts to bind it to 4 different non-internal
          exchanges.
        </doc>
      </rule>
      
      <chassis name = "server" implement = "MUST" />

      <response name = "bind-ok" />
      
      <field name = "ticket" domain = "access-ticket">
        <doc>
          The client provides a valid access ticket giving "active" access rights to the
          queue's access realm.
        </doc>
      </field>
      
      <field name = "queue" domain = "queue-name">
        <doc>
          Specifies the name of the queue to bind. If the queue name is empty, refers to
          the current queue for the channel, which is the last declared queue.
        </doc>
        
        <rule name = "empty-queue" on-failure = "not-allowed">
          <doc>
            A client MUST NOT be allowed to bind a non-existent and unnamed queue (i.e.
            empty queue name) to an exchange.
          </doc>
          <doc type = "scenario">
            A client attempts to bind with an unnamed (empty) queue name to an exchange.
          </doc>
        </rule>
        
        <!-- Rule test name: was "amq_queue_26" -->    
        <rule name = "queue-existence" on-failure = "not-found">
          <doc>
            A client MUST NOT be allowed to bind a non-existent queue (i.e. not previously
            declared) to an exchange.
          </doc>
          <doc type = "scenario">
            A client attempts to bind an undeclared queue name to an exchange.
          </doc>
        </rule>
      </field>
      
      <field name = "exchange" domain = "exchange-name" label = "name of the exchange to bind to">
        <!-- Rule test name: was "amq_queue_14" -->    
        <rule name = "exchange-existence" on-failure = "not-found">
          <doc>
            A client MUST NOT be allowed to bind a queue to a non-existent exchange.
          </doc>
          <doc type = "scenario">
            A client attempts to bind an named queue to a undeclared exchange.
          </doc>
        </rule>
      </field>
      
      <field name = "routing-key" domain = "shortstr" label = "message routing key">
        <doc>
          Specifies the routing key for the binding. The routing key is used for routing
          messages depending on the exchange configuration. Not all exchanges use a
          routing key - refer to the specific exchange documentation.  If the queue name
          is empty, the server uses the last queue declared on the channel.  If the
          routing key is also empty, the server uses this queue name for the routing
          key as well.  If the queue name is provided but the routing key is empty, the
          server does the binding with that empty routing key.  The meaning of empty
          routing keys depends on the exchange implementation.
        </doc>
        <rule name = "direct-exchange-key-matching">
          <doc>
            If a message queue binds to a direct exchange using routing key K and a
            publisher sends the exchange a message with routing key R, then the message
            MUST be passed to the message queue if K = R.
          </doc>
        </rule>
      </field>

      <field name = "nowait" domain = "bit" label = "do not send a reply method">
        <doc>
          If set, the server will not respond to the method. The client should not wait
          for a reply method. If the server could not complete the method it will raise a
          channel or connection exception.
        </doc>
      </field>
      
      <field name = "arguments" domain = "table" label = "arguments for binding">
        <doc>
          A set of arguments for the binding. The syntax and semantics of these arguments
          depends on the exchange class.
        </doc>
      </field>
    </method>
    
    <method name = "bind-ok" synchronous = "1" index = "21" label = "confirm bind successful">
      <doc>This method confirms that the bind was successful.</doc>
      
      <chassis name = "client" implement = "MUST" />
    </method>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "unbind" synchronous = "1" index = "50" label = "unbind a queue from an exchange">
      <doc>This method unbinds a queue from an exchange.</doc>
      <rule name = "01">
        <doc>If a unbind fails, the server MUST raise a connection exception.</doc>
      </rule>
      <chassis name="server" implement="MUST"/>
      <response name="unbind-ok"/>

      <field name = "ticket" domain = "access-ticket">
        <doc>
          The client provides a valid access ticket giving "active"
          access rights to the queue's access realm.
        </doc>
      </field>

      <field name = "queue" domain = "queue-name">
        <doc>Specifies the name of the queue to unbind.</doc>
        <rule name = "02">
          <doc>
            If the queue does not exist the server MUST raise a channel exception
            with reply code 404 (not found).
          </doc>
        </rule>
      </field>

      <field name = "exchange" domain = "exchange-name">
        <doc>The name of the exchange to unbind from.</doc>
        <rule name = "03">
          <doc>
            If the exchange does not exist the server MUST raise a channel
            exception with reply code 404 (not found).
          </doc>
        </rule>
      </field>

      <field name = "routing-key" domain = "shortstr" label = "routing key of binding">
        <doc>Specifies the routing key of the binding to unbind.</doc>
      </field>

      <field name = "arguments" domain = "table" label = "arguments of binding">
        <doc>Specifies the arguments of the binding to unbind.</doc>
      </field>
    </method>

    <method name = "unbind-ok" synchronous = "1" index = "51" label = "confirm unbind successful">
      <doc>This method confirms that the unbind was successful.</doc>
      <chassis name = "client" implement = "MUST"/>
    </method>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->
    
    <method name = "purge" synchronous = "1" index = "30" label = "purge a queue">
      <doc>
        This method removes all messages from a queue. It does not cancel consumers. Purged
        messages are deleted without any formal "undo" mechanism.
      </doc>
      
      <!-- Rule test name: was "amq_queue_15" -->    
      <rule name = "01">
        <doc>A call to purge MUST result in an empty queue.</doc>
      </rule>
      
      <!-- Rule test name: was "amq_queue_41" -->
      <rule name = "02">
        <doc>
          On transacted channels the server MUST not purge messages that have already been
          sent to a client but not yet acknowledged.
        </doc>
      </rule>
      
      <!-- TODO: Rule split? -->
      
      <!-- Rule test name: was "amq_queue_42" -->    
      <rule name = "03">
        <doc>
          The server MAY implement a purge queue or log that allows system administrators
          to recover accidentally-purged messages. The server SHOULD NOT keep purged
          messages in the same storage spaces as the live messages since the volumes of
          purged messages may get very large.
        </doc>
      </rule>
      
      <chassis name = "server" implement = "MUST" />
      
      <response name = "purge-ok" />
      
      <field name = "ticket" domain = "access-ticket">
        <doc>The access ticket must be for the access realm that holds the queue.</doc>
        
        <rule name = "01">
          <doc>
            The client MUST provide a valid access ticket giving "read" access rights to
            the queue's access realm. Note that purging a queue is equivalent to reading
            all messages and discarding them.
          </doc>
        </rule>
      </field>

      <field name = "queue" domain = "queue-name">
        <doc>
          Specifies the name of the queue to purge. If the queue name is empty, refers to
          the current queue for the channel, which is the last declared queue.
        </doc>
        
        <rule name = "01">
          <doc>
            If the client did not previously declare a queue, and the queue name in this
            method is empty, the server MUST raise a connection exception with reply
            code 530 (not allowed).
          </doc>
        </rule>
        
        <!-- TODO Rule split? -->
        
        <!-- Rule test name: was "amq_queue_16" -->    
        <rule name = "02">
          <doc>
            The queue MUST exist. Attempting to purge a non-existing queue MUST cause a
            channel exception.
          </doc>
        </rule>
      </field>
      
      <field name = "nowait" domain = "bit" label = "do not send a reply method">
        <doc>
          If set, the server will not respond to the method. The client should not wait
          for a reply method. If the server could not complete the method it will raise a
          channel or connection exception.
        </doc>
      </field>
    </method>

    <method name = "purge-ok" synchronous = "1" index = "31" label = "confirms a queue purge">
      <doc>This method confirms the purge of a queue.</doc>

      <chassis name = "client" implement = "MUST" />

      <field name = "message-count" domain = "long" label = "number of messages purged">
        <doc>Reports the number of messages purged.</doc>
      </field>
    </method>
    
    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->
    
    <method name = "delete" synchronous = "1" index = "40" label = "delete a queue">
      <doc>
        This method deletes a queue. When a queue is deleted any pending messages are sent
        to a dead-letter queue if this is defined in the server configuration, and all
        consumers on the queue are cancelled.
      </doc>

      <!-- TODO: Rule split? -->

      <!-- Rule test name: was "amq_queue_43" -->
      <rule name = "01">
        <doc>
          The server SHOULD use a dead-letter queue to hold messages that were pending on
          a deleted queue, and MAY provide facilities for a system administrator to move
          these messages back to an active queue.
        </doc>
      </rule>

      <chassis name = "server" implement = "MUST" />

      <response name = "delete-ok" />
      
      <field name = "ticket" domain = "access-ticket">
        <doc>
          The client provides a valid access ticket giving "active" access rights to the
          queue's access realm.
        </doc>
      </field>
      
      <field name = "queue" domain = "queue-name">
        <doc>
          Specifies the name of the queue to delete. If the queue name is empty, refers to
          the current queue for the channel, which is the last declared queue.
        </doc>
        
        <rule name = "01">
          <doc>
            If the client did not previously declare a queue, and the queue name in this
            method is empty, the server MUST raise a connection exception with reply
            code 530 (not allowed).
          </doc>
        </rule>

        <!-- Rule test name: was "amq_queue_21" -->
        <rule name = "02">
          <doc>
            The queue must exist. If the client attempts to delete a non-existing queue
            the server MUST raise a channel exception with reply code 404 (not found).
          </doc>
        </rule>
      </field>

      <field name = "if-unused" domain = "bit" label = "delete only if unused">
        <doc>
          If set, the server will only delete the queue if it has no consumers. If the
          queue has consumers the server does does not delete it but raises a channel
          exception instead.
        </doc>

        <!-- Rule test name: was "amq_queue_29" and "amq_queue_30" -->
        <rule name = "01">
          <doc>The server MUST respect the if-unused flag when deleting a queue.</doc>
        </rule>
      </field>

      <field name = "if-empty" domain = "bit" label = "delete only if empty">
        <doc>
          If set, the server will only delete the queue if it has no messages.
        </doc>
        <rule name = "01">
          <doc>
          If the queue is not empty the server MUST raise a channel exception with
          reply code 406 (precondition failed).
          </doc>
        </rule>
      </field>

      <field name = "nowait" domain = "bit" label = "do not send a reply method">
        <doc>
          If set, the server will not respond to the method. The client should not wait
          for a reply method. If the server could not complete the method it will raise a
          channel or connection exception.
        </doc>
      </field>
    </method>

    <method name = "delete-ok" synchronous = "1" index = "41" label = "confirm deletion of a queue">
      <doc>This method confirms the deletion of a queue.</doc>
      
      <chassis name = "client" implement = "MUST" />
      
      <field name = "message-count" domain = "long" label = "number of messages purged">
        <doc>Reports the number of messages purged.</doc>
      </field>
    </method>
  </class>

  <!-- ==  BASIC  ============================================================ -->

  <class name = "basic" handler = "channel" index = "60" label = "work with basic content">
    <doc>
      The Basic class provides methods that support an industry-standard messaging model.
    </doc>

    <doc type = "grammar">
      basic               = C:QOS S:QOS-OK
                          / C:CONSUME S:CONSUME-OK
                          / C:CANCEL S:CANCEL-OK
                          / C:PUBLISH content
                          / S:RETURN content
                          / S:DELIVER content
                          / C:GET ( S:GET-OK content / S:GET-EMPTY )
                          / C:ACK
                          / C:REJECT
    </doc>

    <chassis name = "server" implement = "MUST" />
    <chassis name = "client" implement = "MAY" />

    <!-- Rule test name: was "amq_basic_08" -->
    <rule name = "01">
      <doc>
        The server SHOULD respect the persistent property of basic messages and
        SHOULD make a best-effort to hold persistent basic messages on a reliable
        storage mechanism.
      </doc>
      <doc type = "scenario">
        Send a persistent message to queue, stop server, restart server and then
        verify whether message is still present.  Assumes that queues are durable.
        Persistence without durable queues makes no sense.
      </doc>
    </rule>

    <!-- Rule test name: was "amq_basic_09" -->
    <rule name = "02">
      <doc>
        The server MUST NOT discard a persistent basic message in case of a queue
        overflow.
      </doc>
      <doc type = "scenario">
        Create a queue overflow situation with persistent messages and verify that
        messages do not get lost (presumably the server will write them to disk).
      </doc>
    </rule>

    <rule name = "03">
      <doc>
        The server MAY use the Channel.Flow method to slow or stop a basic message
        publisher when necessary.
      </doc>
      <doc type = "scenario">
        Create a queue overflow situation with non-persistent messages and verify
        whether the server responds with Channel.Flow or not. Repeat with persistent
        messages.
      </doc>
    </rule>

    <!-- Rule test name: was "amq_basic_10" -->
    <rule name = "04">
      <doc>
        The server MAY overflow non-persistent basic messages to persistent
        storage.
      </doc>
      <!-- Test scenario: untestable -->
    </rule>

    <rule name = "05">
      <doc>
        The server MAY discard or dead-letter non-persistent basic messages on a
        priority basis if the queue size exceeds some configured limit.
      </doc>
      <!-- Test scenario: untestable -->
    </rule>

    <!-- Rule test name: was "amq_basic_11" -->
    <rule name = "06">
      <doc>
        The server MUST implement at least 2 priority levels for basic messages,
        where priorities 0-4 and 5-9 are treated as two distinct levels.
      </doc>
      <doc type = "scenario">
        Send a number of priority 0 messages to a queue. Send one priority 9
        message.  Consume messages from the queue and verify that the first message
        received was priority 9.
      </doc>
    </rule>

    <rule name = "07">
      <doc>
        The server MAY implement up to 10 priority levels.
      </doc>
      <doc type = "scenario">
        Send a number of messages with mixed priorities to a queue, so that all
        priority values from 0 to 9 are exercised. A good scenario would be ten
        messages in low-to-high priority.  Consume from queue and verify how many
        priority levels emerge.
      </doc>
    </rule>

    <!-- Rule test name: was "amq_basic_12" -->
    <rule name = "08">
      <doc>
        The server MUST deliver messages of the same priority in order irrespective of
        their individual persistence.
      </doc>
      <doc type = "scenario">
        Send a set of messages with the same priority but different persistence
        settings to a queue.  Consume and verify that messages arrive in same order
        as originally published.
      </doc>
    </rule>

    <!-- Rule test name: was "amq_basic_13" -->
    <rule name = "09">
      <doc>
        The server MUST support automatic acknowledgements on Basic content, i.e.
        consumers with the no-ack field set to FALSE.
      </doc>
      <doc type = "scenario">
        Create a queue and a consumer using automatic acknowledgements.  Publish
        a set of messages to the queue.  Consume the messages and verify that all
        messages are received.
      </doc>
    </rule>

    <rule name = "10">
      <doc>
        The server MUST support explicit acknowledgements on Basic content, i.e.
        consumers with the no-ack field set to TRUE.
      </doc>
      <doc type = "scenario">
        Create a queue and a consumer using explicit acknowledgements.  Publish a
        set of messages to the queue.  Consume the messages but acknowledge only
        half of them.  Disconnect and reconnect, and consume from the queue.
        Verify that the remaining messages are received.
      </doc>
    </rule>

    <!--  These are the properties for a Basic content  -->

    <field name = "content-type"    domain = "shortstr"   label = "MIME content type" />
    <field name = "content-encoding" domain = "shortstr"  label = "MIME content encoding" />
    <field name = "headers"         domain = "table"      label = "message header field table" />
    <field name = "delivery-mode"   domain = "octet"      label = "non-persistent (1) or persistent (2)" />
    <field name = "priority"        domain = "octet"      label = "message priority, 0 to 9" />
    <field name = "correlation-id"  domain = "shortstr"   label = "application correlation identifier" />
    <field name = "reply-to"        domain = "shortstr"   label = "destination to reply to" />
    <field name = "expiration"      domain = "shortstr"   label = "message expiration specification" />
    <field name = "message-id"      domain = "shortstr"   label = "application message identifier" />
    <field name = "timestamp"       domain = "timestamp"  label = "message timestamp" />
    <field name = "type"            domain = "shortstr"   label = "message type name" />
    <field name = "user-id"         domain = "shortstr"   label = "creating user id" />
    <field name = "app-id"          domain = "shortstr"   label = "creating application id" />
    <!-- This field is deprecated pending review -->
    <field name = "cluster-id"      domain = "shortstr"   label = "intra-cluster routing identifier" />

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "qos" synchronous = "1" index = "10" label = "specify quality of service">
      <doc>
        This method requests a specific quality of service. The QoS can be specified for the
        current channel or for all channels on the connection. The particular properties and
        semantics of a qos method always depend on the content class semantics. Though the
        qos method could in principle apply to both peers, it is currently meaningful only
        for the server.
      </doc>

      <chassis name = "server" implement = "MUST" />
      <response name = "qos-ok" />

      <field name = "prefetch-size" domain = "long" label = "prefetch window in octets">
        <doc>
          The client can request that messages be sent in advance so that when the client
          finishes processing a message, the following message is already held locally,
          rather than needing to be sent down the channel. Prefetching gives a performance
          improvement. This field specifies the prefetch window size in octets. The server
          will send a message in advance if it is equal to or smaller in size than the
          available prefetch size (and also falls into other prefetch limits). May be set
          to zero, meaning "no specific limit", although other prefetch limits may still
          apply. The prefetch-size is ignored if the no-ack option is set.
        </doc>
        <!-- Rule test name: was "amq_basic_17" -->
        <rule name = "01">
          <doc>
            The server MUST ignore this setting when the client is not processing any
            messages - i.e. the prefetch size does not limit the transfer of single
            messages to a client, only the sending in advance of more messages while
            the client still has one or more unacknowledged messages.
          </doc>
          <doc type = "scenario">
            Define a QoS prefetch-size limit and send a single message that exceeds
            that limit.  Verify that the message arrives correctly.
          </doc>
        </rule>
      </field>

      <field name = "prefetch-count" domain = "short" label = "prefetch window in messages">
        <doc>
          Specifies a prefetch window in terms of whole messages. This field may be used
          in combination with the prefetch-size field; a message will only be sent in
          advance if both prefetch windows (and those at the channel and connection level)
          allow it. The prefetch-count is ignored if the no-ack option is set.
        </doc>
        <!-- Rule test name: was "amq_basic_18" -->
        <rule name = "01">
          <doc>
            The server may send less data in advance than allowed by the client's
            specified prefetch windows but it MUST NOT send more.
          </doc>
          <doc type = "scenario">
            Define a QoS prefetch-size limit and a prefetch-count limit greater than
            one.  Send multiple messages that exceed the prefetch size.  Verify that
            no more than one message arrives at once.
          </doc>
        </rule>
      </field>

      <field name = "global" domain = "bit" label = "apply to entire connection">
        <doc>
          By default the QoS settings apply to the current channel only. If this field is
          set, they are applied to the entire connection.
        </doc>
      </field>
    </method>

    <method name = "qos-ok" synchronous = "1" index = "11" label = "confirm the requested qos">
      <doc>
        This method tells the client that the requested QoS levels could be handled by the
        server. The requested QoS applies to all active consumers until a new QoS is
        defined.
      </doc>
      <chassis name = "client" implement = "MUST" />
    </method>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "consume" synchronous = "1" index = "20" label = "start a queue consumer">
      <doc>
        This method asks the server to start a "consumer", which is a transient request for
        messages from a specific queue. Consumers last as long as the channel they were
        created on, or until the client cancels them.
      </doc>

      <!-- Rule test name: was "amq_basic_01" -->
      <rule name = "01">
        <doc>
          The server SHOULD support at least 16 consumers per queue, and ideally, impose
          no limit except as defined by available resources.
        </doc>
        <doc type = "scenario">
          Create a queue and create consumers on that queue until the server closes the
          connection. Verify that the number of consumers created was at least sixteen
          and report the total number.
        </doc>
      </rule>

      <chassis name = "server" implement = "MUST" />
      <response name = "consume-ok" />

      <field name = "ticket" domain = "access-ticket">
        <rule name = "01" on-failure = "access-refused">
          <doc>
            The client MUST provide a valid access ticket giving "read" access rights to
            the realm for the queue.
          </doc>
          <doc type = "scenario">
            Attempt to create a consumer with an invalid (non-zero) access ticket.
          </doc>
        </rule>
      </field>

      <field name = "queue" domain = "queue-name">
        <doc>
          Specifies the name of the queue to consume from. If the queue name is null,
          refers to the current queue for the channel, which is the last declared queue.
        </doc>
        <rule name = "01" on-failure = "not-allowed">
          <doc>
            If the queue name is empty the client MUST have previously declared a
            queue using this channel.
          </doc>
          <doc type = "scenario">
            Attempt to create a consumer with an empty queue name and no previously
            declared queue on the channel.
          </doc>
        </rule>
      </field>

      <field name = "consumer-tag" domain = "consumer-tag">
        <doc>
          Specifies the identifier for the consumer. The consumer tag is local to a
          connection, so two clients can use the same consumer tags. If this field is
          empty the server will generate a unique tag.
        </doc>
        <rule name = "01" on-failure = "not-allowed">
          <doc>
            The client MUST NOT specify a tag that refers to an existing consumer.
          </doc>
          <doc type = "scenario">
            Attempt to create two consumers with the same non-empty tag.
          </doc>
        </rule>
        <rule name = "02" on-failure = "not-allowed">
          <doc>
            The consumer tag is valid only within the channel from which the
            consumer was created. I.e. a client MUST NOT create a consumer in one
            channel and then use it in another.
          </doc>
          <doc type = "scenario">
            Attempt to create a consumer in one channel, then use in another channel,
            in which consumers have also been created (to test that the server uses
            unique consumer tags).
          </doc>
        </rule>
      </field>

      <field name = "no-local" domain = "no-local" />

      <field name = "no-ack" domain = "no-ack" />

      <field name = "exclusive" domain = "bit" label = "request exclusive access">
        <doc>
          Request exclusive consumer access, meaning only this consumer can access the
          queue.
        </doc>
        <!-- Rule test name: was "amq_basic_02" -->
        <rule name = "01" on-failure = "access-refused">
          <doc>
            The client MAY NOT gain exclusive access to a queue that already has
            active consumers.
          </doc>
          <doc type = "scenario">
            Open two connections to a server, and in one connection create a shared
            (non-exclusive) queue and then consume from the queue.  In the second
            connection attempt to consume from the same queue using the exclusive
            option.
          </doc>
        </rule>
      </field>

      <field name = "nowait" domain = "bit" label = "do not send a reply method">
        <doc>
          If set, the server will not respond to the method. The client should not wait
          for a reply method. If the server could not complete the method it will raise
          a channel or connection exception.
        </doc>
      </field>
      
      <field name = "filter" domain = "table" label = "arguments for consuming">
      	<doc>
          A set of filters for the consume. The syntax and semantics
		  of these filters depends on the providers implementation.
        </doc>
      </field>
    </method>

    <method name = "consume-ok" synchronous = "1" index = "21" label = "confirm a new consumer">
      <doc>
        The server provides the client with a consumer tag, which is used by the client
        for methods called on the consumer at a later stage.
      </doc>
      <chassis name = "client" implement = "MUST" />
      <field name = "consumer-tag" domain = "consumer-tag">
        <doc>
          Holds the consumer tag specified by the client or provided by the server.
        </doc>
      </field>
    </method>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "cancel" synchronous = "1" index = "30" label = "end a queue consumer">
      <doc>
        This method cancels a consumer. This does not affect already delivered
        messages, but it does mean the server will not send any more messages for
        that consumer. The client may receive an arbitrary number of messages in
        between sending the cancel method and receiving the cancel-ok reply.
      </doc>

      <rule name = "01">
        <doc>
          If the queue does not exist the server MUST ignore the cancel method, so
          long as the consumer tag is valid for that channel.
        </doc>
        <doc type = "scenario">
          TODO.
        </doc>
      </rule>

      <chassis name = "server" implement = "MUST" />
      <response name = "cancel-ok" />

      <field name = "consumer-tag" domain = "consumer-tag" />

      <field name = "nowait" domain = "bit" label = "do not send a reply method">
        <doc>
          If set, the server will not respond to the method. The client should not wait
          for a reply method. If the server could not complete the method it will raise a
          channel or connection exception.
        </doc>
      </field>
    </method>

    <method name = "cancel-ok" synchronous = "1" index = "31" label = "confirm a cancelled consumer">
      <doc>
        This method confirms that the cancellation was completed.
      </doc>
      <chassis name = "client" implement = "MUST" />
      <field name = "consumer-tag" domain = "consumer-tag" />
    </method>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "publish" content = "1" index = "40" label = "publish a message">
      <doc>
        This method publishes a message to a specific exchange. The message will be routed
        to queues as defined by the exchange configuration and distributed to any active
        consumers when the transaction, if any, is committed.
      </doc>

      <chassis name = "server" implement = "MUST" />

      <field name = "ticket" domain = "access-ticket">
        <rule name = "01">
          <doc>
            The client MUST provide a valid access ticket giving "write" access rights
            to the access realm for the exchange.
          </doc>
          <doc type = "scenario">
            TODO.
          </doc>
        </rule>
      </field>

      <field name = "exchange" domain = "exchange-name">
        <doc>
          Specifies the name of the exchange to publish to. The exchange name can be
          empty, meaning the default exchange. If the exchange name is specified, and that
          exchange does not exist, the server will raise a channel exception.
        </doc>

        <!-- Rule test name: was "amq_basic_06" -->
        <rule name = "01">
          <doc>
            The server MUST accept a blank exchange name to mean the default exchange.
          </doc>
          <doc type = "scenario">
            TODO.
          </doc>
        </rule>

        <!-- Rule test name: was "amq_basic_14" -->
        <rule name = "02">
          <doc>
            If the exchange was declared as an internal exchange, the server MUST raise
            a channel exception with a reply code 403 (access refused).
          </doc>
          <doc type = "scenario">
            TODO.
          </doc>
        </rule>

        <!-- Rule test name: was "amq_basic_15" -->
        <rule name = "03">
          <doc>
            The exchange MAY refuse basic content in which case it MUST raise a channel
            exception with reply code 540 (not implemented).
          </doc>
          <doc type = "scenario">
            TODO.
          </doc>
        </rule>
      </field>

      <field name = "routing-key" domain = "shortstr" label = "Message routing key">
        <doc>
          Specifies the routing key for the message. The routing key is used for routing
          messages depending on the exchange configuration.
        </doc>
      </field>

      <field name = "mandatory" domain = "bit" label = "indicate mandatory routing">
        <doc>
          This flag tells the server how to react if the message cannot be routed to a
          queue. If this flag is set, the server will return an unroutable message with a
          Return method. If this flag is zero, the server silently drops the message.
        </doc>
        <!-- Rule test name: was "amq_basic_07" -->
        <rule name = "01">
          <doc>
            The server SHOULD implement the mandatory flag.
          </doc>
          <doc type = "scenario">
            TODO.
          </doc>
        </rule>
      </field>

      <field name = "immediate" domain = "bit" label = "request immediate delivery">
        <doc>
          This flag tells the server how to react if the message cannot be routed to a
          queue consumer immediately. If this flag is set, the server will return an
          undeliverable message with a Return method. If this flag is zero, the server
          will queue the message, but with no guarantee that it will ever be consumed.
        </doc>
        <!-- Rule test name: was "amq_basic_16" -->
        <rule name = "01">
          <doc>
            The server SHOULD implement the immediate flag.
          </doc>
          <doc type = "scenario">
            TODO.
          </doc>
        </rule>
      </field>
    </method>

    <method name = "return" content = "1" index = "50" label = "return a failed message">
      <doc>
        This method returns an undeliverable message that was published with the "immediate"
        flag set, or an unroutable message published with the "mandatory" flag set. The
        reply code and text provide information about the reason that the message was
        undeliverable.
      </doc>

      <chassis name = "client" implement = "MUST" />

      <field name = "reply-code" domain = "reply-code" />

      <field name = "reply-text" domain = "reply-text" />

      <field name = "exchange" domain = "exchange-name">
        <doc>
          Specifies the name of the exchange that the message was originally published to.
        </doc>
      </field>

      <field name = "routing-key" domain = "shortstr" label = "Message routing key">
        <doc>
          Specifies the routing key name specified when the message was published.
        </doc>
      </field>
    </method>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "deliver" content = "1" index = "60"
      label = "notify the client of a consumer message">
      <doc>
        This method delivers a message to the client, via a consumer. In the asynchronous
        message delivery model, the client starts a consumer using the Consume method, then
        the server responds with Deliver methods as and when messages arrive for that
        consumer.
      </doc>

      <!-- Rule test name: was "amq_basic_19" -->
      <rule name = "01">
        <!-- TODO: Rule split? -->
        <doc>
          The server SHOULD track the number of times a message has been delivered to
          clients and when a message is redelivered a certain number of times - e.g. 5
          times - without being acknowledged, the server SHOULD consider the message to be
          unprocessable (possibly causing client applications to abort), and move the
          message to a dead letter queue.
        </doc>
        <doc type = "scenario">
          TODO.
        </doc>
      </rule>

      <chassis name = "client" implement = "MUST" />

      <field name = "consumer-tag" domain = "consumer-tag" />

      <field name = "delivery-tag" domain = "delivery-tag" />

      <field name = "redelivered" domain = "redelivered" />

      <field name = "exchange" domain = "exchange-name">
        <doc>
          Specifies the name of the exchange that the message was originally published to.
        </doc>
      </field>

      <field name = "routing-key" domain = "shortstr" label = "Message routing key">
        <doc>Specifies the routing key name specified when the message was published.</doc>
      </field>
    </method>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "get" synchronous = "1" index = "70" label = "direct access to a queue">
      <doc>
        This method provides a direct access to the messages in a queue using a synchronous
        dialogue that is designed for specific types of application where synchronous
        functionality is more important than performance.
      </doc>

      <response name = "get-ok" />
      <response name = "get-empty" />
      <chassis name = "server" implement = "MUST" />

      <field name = "ticket" domain = "access-ticket">
        <rule name = "01">
          <doc>
            The client MUST provide a valid access ticket giving "read" access rights to
            the realm for the queue.
          </doc>
          <doc type = "scenario">
            TODO.
          </doc>
        </rule>
      </field>

      <field name = "queue" domain = "queue-name">
        <doc>
          Specifies the name of the queue to consume from. If the queue name is null,
          refers to the current queue for the channel, which is the last declared queue.
        </doc>
        <rule name = "01">
          <doc>
            If the client did not previously declare a queue, and the queue name in this
            method is empty, the server MUST raise a connection exception with reply
            code 530 (not allowed).
          </doc>
          <doc type = "scenario">
            TODO.
          </doc>
        </rule>
      </field>

      <field name = "no-ack" domain = "no-ack" />
    </method>

    <method name = "get-ok" synchronous = "1" content = "1" index = "71"
      label = "provide client with a message">
      <doc>
        This method delivers a message to the client following a get method. A message
        delivered by 'get-ok' must be acknowledged unless the no-ack option was set in the
        get method.
      </doc>

      <chassis name = "client" implement = "MAY" />

      <field name = "delivery-tag" domain = "delivery-tag" />

      <field name = "redelivered" domain = "redelivered" />

      <field name = "exchange" domain = "exchange-name">
        <doc>
          Specifies the name of the exchange that the message was originally published to.
          If empty, the message was published to the default exchange.
        </doc>
      </field>

      <field name = "routing-key" domain = "shortstr" label = "Message routing key">
        <doc>Specifies the routing key name specified when the message was published.</doc>
      </field>

      <field name = "message-count" domain = "long" label = "number of messages pending">
        <doc>
          This field reports the number of messages pending on the queue, excluding the
          message being delivered. Note that this figure is indicative, not reliable, and
          can change arbitrarily as messages are added to the queue and removed by other
          clients.
        </doc>
      </field>
    </method>

    <method name = "get-empty" synchronous = "1" index = "72"
      label = "indicate no messages available">
      <doc>
        This method tells the client that the queue has no messages available for the
        client.
      </doc>

      <chassis name = "client" implement = "MAY" />

      <!-- This field is deprecated pending review -->
      <field name = "cluster-id" domain = "shortstr" label = "Cluster id">
        <doc>
          For use by cluster applications, should not be used by client applications.
        </doc>
      </field>
    </method>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "ack" index = "80" label = "acknowledge one or more messages">
      <doc>
        This method acknowledges one or more messages delivered via the Deliver or Get-Ok
        methods. The client can ask to confirm a single message or a set of messages up to
        and including a specific message.
      </doc>

      <chassis name = "server" implement = "MUST" />

      <field name = "delivery-tag" domain = "delivery-tag" />

      <field name = "multiple" domain = "bit" label = "acknowledge multiple messages">
        <doc>
          If set to 1, the delivery tag is treated as "up to and including", so that the
          client can acknowledge multiple messages with a single method. If set to zero,
          the delivery tag refers to a single message. If the multiple field is 1, and the
          delivery tag is zero, tells the server to acknowledge all outstanding messages.
        </doc>

        <!-- Rule test name: was "amq_basic_20" -->
        <rule name = "01">
          <doc>
            The server MUST validate that a non-zero delivery-tag refers to an delivered
            message, and raise a channel exception if this is not the case.
          </doc>
          <doc type = "scenario">
            TODO.
          </doc>
        </rule>
      </field>
    </method>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "reject" index = "90" label = "reject an incoming message">
      <doc>
        This method allows a client to reject a message. It can be used to interrupt and
        cancel large incoming messages, or return untreatable messages to their original
        queue.
      </doc>

      <!-- Rule test name: was "amq_basic_21" -->
      <rule name = "01">
        <doc>
          The server SHOULD be capable of accepting and process the Reject method while
          sending message content with a Deliver or Get-Ok method. I.e. the server should
          read and process incoming methods while sending output frames. To cancel a
          partially-send content, the server sends a content body frame of size 1 (i.e.
          with no data except the frame-end octet).
        </doc>
      </rule>

      <!-- Rule test name: was "amq_basic_22" -->
      <rule name = "02">
        <doc>
          The server SHOULD interpret this method as meaning that the client is unable to
          process the message at this time.
        </doc>
        <doc type = "scenario">
          TODO.
        </doc>
      </rule>

      <rule name = "03">
        <!-- TODO: Rule split? -->
        <doc>
          A client MUST NOT use this method as a means of selecting messages to process. A
          rejected message MAY be discarded or dead-lettered, not necessarily passed to
          another client.
        </doc>
        <doc type = "scenario">
          TODO.
        </doc>
      </rule>

      <chassis name = "server" implement = "MUST" />

      <field name = "delivery-tag" domain = "delivery-tag" />

      <field name = "requeue" domain = "bit" label = "requeue the message">
        <doc>
          If this field is zero, the message will be discarded. If this bit is 1, the
          server will attempt to requeue the message.
        </doc>

        <!-- Rule test name: was "amq_basic_23" -->
        <rule name = "01">
          <!-- TODO: Rule split? -->
          <doc>
            The server MUST NOT deliver the message to the same client within the
            context of the current channel. The recommended strategy is to attempt to
            deliver the message to an alternative consumer, and if that is not possible,
            to move the message to a dead-letter queue. The server MAY use more
            sophisticated tracking to hold the message on the queue and redeliver it to
            the same client at a later stage.
          </doc>
          <doc type = "scenario">
            TODO.
          </doc>
        </rule>
      </field>
    </method>

    <method name = "recover" index = "100" label = "redeliver unacknowledged messages">
      <doc>
        This method asks the broker to redeliver all unacknowledged messages on a specified
        channel. Zero or more messages may be redelivered. This method is only allowed on
        non-transacted channels.
      </doc>

      <rule name = "01">
        <doc>
          The server MUST set the redelivered flag on all messages that are resent.
        </doc>
        <doc type = "scenario">
          TODO.
        </doc>
      </rule>

      <rule name = "02">
        <doc>
          The server MUST raise a channel exception if this is called on a transacted
          channel.
        </doc>
        <doc type = "scenario">
          TODO.
        </doc>
      </rule>

      <chassis name = "server" implement = "MUST" />

      <field name = "requeue" domain = "bit" label = "requeue the message">
        <doc>
          If this field is zero, the message will be redelivered to the original
          recipient. If this bit is 1, the server will attempt to requeue the message,
          potentially then delivering it to an alternative subscriber.
        </doc>
      </field>
    </method>
  </class>

  <!-- ==  FILE  ============================================================= -->

  <class name = "file" handler = "channel" index = "70" label = "work with file content">
    <doc>
      The file class provides methods that support reliable file transfer. File
      messages have a specific set of properties that are required for interoperability
      with file transfer applications. File messages and acknowledgements are subject to
      channel transactions. Note that the file class does not provide message browsing
      methods; these are not compatible with the staging model. Applications that need
      browsable file transfer should use Basic content and the Basic class.
    </doc>

    <doc type = "grammar">
      file                = C:QOS S:QOS-OK
                          / C:CONSUME S:CONSUME-OK
                          / C:CANCEL S:CANCEL-OK
                          / C:OPEN S:OPEN-OK C:STAGE content
                          / S:OPEN C:OPEN-OK S:STAGE content
                          / C:PUBLISH
                          / S:DELIVER
                          / S:RETURN
                          / C:ACK
                          / C:REJECT
    </doc>

    <chassis name = "server" implement = "MAY" />
    <chassis name = "client" implement = "MAY" />

    <rule name = "01">
      <doc>
        The server MUST make a best-effort to hold file messages on a reliable storage
        mechanism.
      </doc>
    </rule>

    <!-- TODO Rule implement attr inverse? -->

    <!-- TODO: Rule split? -->

    <rule name = "02">
      <doc>
        The server MUST NOT discard a file message in case of a queue overflow. The server
        MUST use the Channel.Flow method to slow or stop a file message publisher when
        necessary.
      </doc>
    </rule>

    <!-- TODO: Rule split? -->

    <rule name = "03">
      <doc>
        The server MUST implement at least 2 priority levels for file messages, where
        priorities 0-4 and 5-9 are treated as two distinct levels. The server MAY implement
        up to 10 priority levels.
      </doc>
    </rule>
    
    <rule name = "04">
      <doc>
        The server MUST support both automatic and explicit acknowledgements on file
        content.
      </doc>
    </rule>
    
    <!--  These are the properties for a File content  -->

    <field name = "content-type"    domain = "shortstr"   label = "MIME content type" />
    <field name = "content-encoding" domain = "shortstr"  label = "MIME content encoding" />
    <field name = "headers"         domain = "table"      label = "message header field table" />
    <field name = "priority"        domain = "octet"      label = "message priority, 0 to 9" />
    <field name = "reply-to"        domain = "shortstr"   label = "destination to reply to" />
    <field name = "message-id"      domain = "shortstr"   label = "application message identifier" />
    <field name = "filename"        domain = "shortstr"   label = "message filename" />
    <field name = "timestamp"       domain = "timestamp"  label = "message timestamp" />
    <!-- This field is deprecated pending review -->
    <field name = "cluster-id"      domain = "shortstr"   label = "intra-cluster routing identifier" />

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "qos" synchronous = "1" index = "10" label = "specify quality of service">
      <doc>
        This method requests a specific quality of service. The QoS can be specified for the
        current channel or for all channels on the connection. The particular properties and
        semantics of a qos method always depend on the content class semantics. Though the
        qos method could in principle apply to both peers, it is currently meaningful only
        for the server.
      </doc>
      
      <chassis name = "server" implement = "MUST" />
      
      <response name = "qos-ok" />
      
      <field name = "prefetch-size" domain = "long" label = "prefetch window in octets">
        <doc>
          The client can request that messages be sent in advance so that when the client
          finishes processing a message, the following message is already held locally,
          rather than needing to be sent down the channel. Prefetching gives a performance
          improvement. This field specifies the prefetch window size in octets. May be set
          to zero, meaning "no specific limit". Note that other prefetch limits may still
          apply. The prefetch-size is ignored if the no-ack option is set.
        </doc>
      </field>
      
      <field name = "prefetch-count" domain = "short" label = "prefetch window in messages">
        <doc>
          Specifies a prefetch window in terms of whole messages. This is compatible with
          some file API implementations. This field may be used in combination with the
          prefetch-size field; a message will only be sent in advance if both prefetch
          windows (and those at the channel and connection level) allow it. The
          prefetch-count is ignored if the no-ack option is set.
        </doc>
        
        <rule name = "01">
          <!-- TODO: Rule split? -->
          <doc>
            The server MAY send less data in advance than allowed by the client's
            specified prefetch windows but it MUST NOT send more.
          </doc>
        </rule>
      </field>
      
      <field name = "global" domain = "bit" label = "apply to entire connection">
        <doc>
          By default the QoS settings apply to the current channel only. If this field is
          set, they are applied to the entire connection.
        </doc>
      </field>
    </method>
    
    <method name = "qos-ok" synchronous = "1" index = "11" label = "confirm the requested qos">
      <doc>
        This method tells the client that the requested QoS levels could be handled by the
        server. The requested QoS applies to all active consumers until a new QoS is
        defined.
      </doc>
      
      <chassis name = "client" implement = "MUST" />
    </method>
    
    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->
    
    <method name = "consume" synchronous = "1" index = "20" label = "start a queue consumer">
      <doc>
        This method asks the server to start a "consumer", which is a transient request for
        messages from a specific queue. Consumers last as long as the channel they were
        created on, or until the client cancels them.
      </doc>
      
      <rule name = "01">
        <doc>
          The server SHOULD support at least 16 consumers per queue, unless the queue was
          declared as private, and ideally, impose no limit except as defined by available
          resources.
        </doc>
      </rule>
      
      <chassis name = "server" implement = "MUST" />
      
      <response name = "consume-ok" />
      
      <field name = "ticket" domain = "access-ticket">
        <rule name = "01">
          <doc>
            The client MUST provide a valid access ticket giving "read" access rights to
            the realm for the queue.
          </doc>
        </rule>
      </field>
      
      <field name = "queue" domain = "queue-name">
        <doc>
          Specifies the name of the queue to consume from. If the queue name is null,
          refers to the current queue for the channel, which is the last declared queue.
        </doc>
        
        <rule name = "01">
          <doc>
            If the client did not previously declare a queue, and the queue name in this
            method is empty, the server MUST raise a connection exception with reply
            code 530 (not allowed).
          </doc>
        </rule>
      </field>
      
      <field name = "consumer-tag" domain = "consumer-tag">
        <doc>
          Specifies the identifier for the consumer. The consumer tag is local to a
          connection, so two clients can use the same consumer tags. If this field is
          empty the server will generate a unique tag.
        </doc>
        
        <rule name = "01">
          <!-- TODO: Rule split? -->
          <doc>
            The tag MUST NOT refer to an existing consumer. If the client attempts to
            create two consumers with the same non-empty tag the server MUST raise a
            connection exception with reply code 530 (not allowed).
          </doc>
        </rule>
      </field>
      
      <field name = "no-local" domain = "no-local" />
      
      <field name = "no-ack" domain = "no-ack" />
      
      <field name = "exclusive" domain = "bit" label = "request exclusive access">
        <doc>
          Request exclusive consumer access, meaning only this consumer can access the
          queue.
        </doc>

        <!-- Rule test name: was "amq_file_00" -->    
        <rule name = "01">
          <doc>
            If the server cannot grant exclusive access to the queue when asked, -
            because there are other consumers active - it MUST raise a channel exception
            with return code 405 (resource locked).
          </doc>
        </rule>
      </field>
      
      <field name = "nowait" domain = "bit" label = "do not send a reply method">
        <doc>
          If set, the server will not respond to the method. The client should not wait
          for a reply method. If the server could not complete the method it will raise a
          channel or connection exception.
        </doc>
      </field>
      
      <field name = "filter" domain = "table" label = "arguments for consuming">
      	<doc>
          A set of filters for the consume. The syntax and semantics
		  of these filters depends on the providers implementation.
        </doc>
      </field>
    </method>
    
    <method name = "consume-ok" synchronous = "1" index = "21" label = "confirm a new consumer">
      <doc>
        This method provides the client with a consumer tag which it MUST use in methods
        that work with the consumer.
      </doc>
      
      <chassis name = "client" implement = "MUST" />
      
      <field name = "consumer-tag" domain = "consumer-tag">
        <doc>Holds the consumer tag specified by the client or provided by the server.</doc>
      </field>
    </method>
    
    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->
    
    <method name = "cancel" synchronous = "1" index = "30" label = "end a queue consumer">
      <doc>
        This method cancels a consumer. This does not affect already delivered messages, but
        it does mean the server will not send any more messages for that consumer.
      </doc>

      <response name = "cancel-ok" />

      <chassis name = "server" implement = "MUST" />

      <field name = "consumer-tag" domain = "consumer-tag" />

      <field name = "nowait" domain = "bit" label = "do not send a reply method">
        <doc>
          If set, the server will not respond to the method. The client should not wait
          for a reply method. If the server could not complete the method it will raise a
          channel or connection exception.
        </doc>
      </field>
    </method>

    <method name = "cancel-ok" synchronous = "1" index = "31" label = "confirm a cancelled consumer">
      <doc>This method confirms that the cancellation was completed.</doc>

      <chassis name = "client" implement = "MUST" />

      <field name = "consumer-tag" domain = "consumer-tag" />
    </method>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "open" synchronous = "1" index = "40" label = "request to start staging">
      <doc>
        This method requests permission to start staging a message. Staging means sending
        the message into a temporary area at the recipient end and then delivering the
        message by referring to this temporary area. Staging is how the protocol handles
        partial file transfers - if a message is partially staged and the connection breaks,
        the next time the sender starts to stage it, it can restart from where it left off.
      </doc>

      <response name = "open-ok" />

      <chassis name = "server" implement = "MUST" />
      <chassis name = "client" implement = "MUST" />

      <field name = "identifier" domain = "shortstr" label = "staging identifier">
        <doc>
          This is the staging identifier. This is an arbitrary string chosen by the
          sender. For staging to work correctly the sender must use the same staging
          identifier when staging the same message a second time after recovery from a
          failure. A good choice for the staging identifier would be the SHA1 hash of the
          message properties data (including the original filename, revised time, etc.).
        </doc>
      </field>
      
      <field name = "content-size" domain = "longlong" label = "message content size">
        <doc>
          The size of the content in octets. The recipient may use this information to
          allocate or check available space in advance, to avoid "disk full" errors during
          staging of very large messages.
        </doc>
        
        <rule name = "01">
          <doc>
            The sender MUST accurately fill the content-size field. Zero-length content
            is permitted.
          </doc>
        </rule>
      </field>
    </method>
    
    <method name = "open-ok" synchronous = "1" index = "41" label = "confirm staging ready">
      <doc>
        This method confirms that the recipient is ready to accept staged data. If the
        message was already partially-staged at a previous time the recipient will report
        the number of octets already staged.
      </doc>
      
      <response name = "stage" />
      
      <chassis name = "server" implement = "MUST" />
      <chassis name = "client" implement = "MUST" />

      <field name = "staged-size" domain = "longlong" label = "already staged amount">
        <doc>
          The amount of previously-staged content in octets. For a new message this will
          be zero.
        </doc>
        
        <rule name = "01">
          <doc>
            The sender MUST start sending data from this octet offset in the message,
            counting from zero.
          </doc>
        </rule>
        
        <rule name = "02">
          <!-- TODO: Rule split? -->
          <doc>
            The recipient MAY decide how long to hold partially-staged content and MAY
            implement staging by always discarding partially-staged content. However if
            it uses the file content type it MUST support the staging methods.
          </doc>
        </rule>
      </field>
    </method>
    
    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->
    
    <method name = "stage" content = "1" index = "50" label = "stage message content">
      <doc>
        This method stages the message, sending the message content to the recipient from
        the octet offset specified in the Open-Ok method.
      </doc>
      
      <chassis name = "server" implement = "MUST" />
      <chassis name = "client" implement = "MUST" />
    </method>
    
    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->
    
    <method name = "publish" index = "60" label = "publish a message">
      <doc>
        This method publishes a staged file message to a specific exchange. The file message
        will be routed to queues as defined by the exchange configuration and distributed to
        any active consumers when the transaction, if any, is committed.
      </doc>
      
      <chassis name = "server" implement = "MUST" />

      <field name = "ticket" domain = "access-ticket">
        <rule name = "01">
          <doc>
            The client MUST provide a valid access ticket giving "write" access rights
            to the access realm for the exchange.
          </doc>
        </rule>
      </field>
      
      <field name = "exchange" domain = "exchange-name">
        <doc>
          Specifies the name of the exchange to publish to. The exchange name can be
          empty, meaning the default exchange. If the exchange name is specified, and that
          exchange does not exist, the server will raise a channel exception.
        </doc>
        
        <rule name = "01">
          <doc>
            The server MUST accept a blank exchange name to mean the default exchange.
          </doc>
        </rule>
        
        <rule name = "02">
          <doc>
            If the exchange was declared as an internal exchange, the server MUST
            respond with a reply code 403 (access refused) and raise a channel
            exception.
          </doc>
        </rule>
        
        <!-- TODO: Rule split? -->
        
        <rule name = "03">
          <doc>
            The exchange MAY refuse file content in which case it MUST respond with a
            reply code 540 (not implemented) and raise a channel exception.
          </doc>
        </rule>
      </field>
      
      <field name = "routing-key" domain = "shortstr" label = "Message routing key">
        <doc>
          Specifies the routing key for the message. The routing key is used for routing
          messages depending on the exchange configuration.
        </doc>
      </field>
      
      <field name = "mandatory" domain = "bit" label = "indicate mandatory routing">
        <doc>
          This flag tells the server how to react if the message cannot be routed to a
          queue. If this flag is set, the server will return an unroutable message with a
          Return method. If this flag is zero, the server silently drops the message.
        </doc>
        
        <!-- Rule test name: was "amq_file_00" -->    
        <rule name = "01">
          <doc>The server SHOULD implement the mandatory flag.</doc>
        </rule>
      </field>
      
      <field name = "immediate" domain = "bit" label = "request immediate delivery">
        <doc>
          This flag tells the server how to react if the message cannot be routed to a
          queue consumer immediately. If this flag is set, the server will return an
          undeliverable message with a Return method. If this flag is zero, the server
          will queue the message, but with no guarantee that it will ever be consumed.
        </doc>
                
        <!-- Rule test name: was "amq_file_00" -->    
        <rule name = "01">
          <doc>The server SHOULD implement the immediate flag.</doc>
        </rule>
      </field>
      
      <field name = "identifier" domain = "shortstr" label = "staging identifier">
        <doc>
          This is the staging identifier of the message to publish. The message must have
          been staged. Note that a client can send the Publish method asynchronously
          without waiting for staging to finish.
        </doc>
      </field>
    </method>
    
    <method name = "return" content = "1" index = "70" label = "return a failed message">
      <doc>
        This method returns an undeliverable message that was published with the "immediate"
        flag set, or an unroutable message published with the "mandatory" flag set. The
        reply code and text provide information about the reason that the message was
        undeliverable.
      </doc>
      
      <chassis name = "client" implement = "MUST" />
      
      <field name = "reply-code" domain = "reply-code" />
      
      <field name = "reply-text" domain = "reply-text" />
      
      <field name = "exchange" domain = "exchange-name">
        <doc>
          Specifies the name of the exchange that the message was originally published to.
        </doc>
      </field>

      <field name = "routing-key" domain = "shortstr" label = "Message routing key">
        <doc>Specifies the routing key name specified when the message was published.</doc>
      </field>
    </method>
    
    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->
    
    <method name = "deliver" index = "80" label = "notify the client of a consumer message">
      <doc>
        This method delivers a staged file message to the client, via a consumer. In the
        asynchronous message delivery model, the client starts a consumer using the Consume
        method, then the server responds with Deliver methods as and when messages arrive
        for that consumer.
      </doc>
      
      <rule name = "01">
        <!-- TODO: Rule split? -->
        <doc>
          The server SHOULD track the number of times a message has been delivered to
          clients and when a message is redelivered a certain number of times - e.g. 5
          times - without being acknowledged, the server SHOULD consider the message to be
          unprocessable (possibly causing client applications to abort), and move the
          message to a dead letter queue.
        </doc>
      </rule>
      
      <chassis name = "client" implement = "MUST" />
      
      <field name = "consumer-tag" domain = "consumer-tag" />
      
      <field name = "delivery-tag" domain = "delivery-tag" />
      
      <field name = "redelivered" domain = "redelivered" />
      
      <field name = "exchange" domain = "exchange-name">
        <doc>
          Specifies the name of the exchange that the message was originally published to.
        </doc>
      </field>
      
      <field name = "routing-key" domain = "shortstr" label = "Message routing key">
        <doc>Specifies the routing key name specified when the message was published.</doc>
      </field>
      
      <field name = "identifier" domain = "shortstr" label = "staging identifier">
        <doc>
          This is the staging identifier of the message to deliver. The message must have
          been staged. Note that a server can send the Deliver method asynchronously
          without waiting for staging to finish.
        </doc>
      </field>
    </method>
    
    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->
    
    <method name = "ack" index = "90" label = "acknowledge one or more messages">
      <doc>
        This method acknowledges one or more messages delivered via the Deliver method. The
        client can ask to confirm a single message or a set of messages up to and including
        a specific message.
      </doc>
      
      <chassis name = "server" implement = "MUST" />
      
      <field name = "delivery-tag" domain = "delivery-tag" />
      
      <field name = "multiple" domain = "bit" label = "acknowledge multiple messages">
        <doc>
          If set to 1, the delivery tag is treated as "up to and including", so that the
          client can acknowledge multiple messages with a single method. If set to zero,
          the delivery tag refers to a single message. If the multiple field is 1, and the
          delivery tag is zero, tells the server to acknowledge all outstanding messages.
        </doc>
        
        <rule name = "01">
          <doc>
            The server MUST validate that a non-zero delivery-tag refers to an delivered
            message, and raise a channel exception if this is not the case.
          </doc>
        </rule>
      </field>
    </method>
    
    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->
    
    <method name = "reject" index = "100" label = "reject an incoming message">
      <doc>
        This method allows a client to reject a message. It can be used to return
        untreatable messages to their original queue. Note that file content is staged
        before delivery, so the client will not use this method to interrupt delivery of a
        large message.
      </doc>
      
      <rule name = "01">
        <doc>
          The server SHOULD interpret this method as meaning that the client is unable to
          process the message at this time.
        </doc>
      </rule>
      
      <!-- TODO: Rule split? -->
      
      <rule name = "02">
        <doc>
          A client MUST NOT use this method as a means of selecting messages to process. A
          rejected message MAY be discarded or dead-lettered, not necessarily passed to
          another client.
        </doc>
      </rule>
      
      <chassis name = "server" implement = "MUST" />
      
      <field name = "delivery-tag" domain = "delivery-tag" />
      
      <field name = "requeue" domain = "bit" label = "requeue the message">
        <doc>
          If this field is zero, the message will be discarded. If this bit is 1, the
          server will attempt to requeue the message.
        </doc>
        
        <rule name = "01">
          <!-- TODO: Rule split? -->
          <doc>
            The server MUST NOT deliver the message to the same client within the
            context of the current channel. The recommended strategy is to attempt to
            deliver the message to an alternative consumer, and if that is not possible,
            to move the message to a dead-letter queue. The server MAY use more
            sophisticated tracking to hold the message on the queue and redeliver it to
            the same client at a later stage.
          </doc>
        </rule>
      </field>
    </method>
  </class>

  <!-- ==  STREAM  =========================================================== -->

  <class name = "stream" handler = "channel" index = "80" label = "work with streaming content">
    <doc>
      The stream class provides methods that support multimedia streaming. The stream class
      uses the following semantics: one message is one packet of data; delivery is
      unacknowledged and unreliable; the consumer can specify quality of service parameters
      that the server can try to adhere to; lower-priority messages may be discarded in favour
      of high priority messages.
    </doc>
    
    <doc type = "grammar">
      stream              = C:QOS S:QOS-OK
                          / C:CONSUME S:CONSUME-OK
                          / C:CANCEL S:CANCEL-OK
                          / C:PUBLISH content
                          / S:RETURN
                          / S:DELIVER content
    </doc>

    <chassis name = "server" implement = "MAY" />
    <chassis name = "client" implement = "MAY" />

    <rule name = "01">
      <doc>
        The server SHOULD discard stream messages on a priority basis if the queue size
        exceeds some configured limit.
      </doc>
    </rule>
    
    <rule name = "02">
      <!-- TODO: Rule split? -->
      <doc>
        The server MUST implement at least 2 priority levels for stream messages, where
        priorities 0-4 and 5-9 are treated as two distinct levels. The server MAY implement
        up to 10 priority levels.
      </doc>
    </rule>
    
    <rule name = "03">
      <doc>
        The server MUST implement automatic acknowledgements on stream content. That is, as
        soon as a message is delivered to a client via a Deliver method, the server must
        remove it from the queue.
      </doc>
    </rule>
    
    <!--  These are the properties for a Stream content  -->

    <field name = "content-type"    domain = "shortstr"   label = "MIME content type" />
    <field name = "content-encoding" domain = "shortstr"  label = "MIME content encoding" />
    <field name = "headers"         domain = "table"      label = "message header field table" />
    <field name = "priority"        domain = "octet"      label = "message priority, 0 to 9" />
    <field name = "timestamp"       domain = "timestamp"  label = "message timestamp" />

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "qos" synchronous = "1" index = "10" label = "specify quality of service">
      <doc>
        This method requests a specific quality of service. The QoS can be specified for the
        current channel or for all channels on the connection. The particular properties and
        semantics of a qos method always depend on the content class semantics. Though the
        qos method could in principle apply to both peers, it is currently meaningful only
        for the server.
      </doc>
      
      <chassis name = "server" implement = "MUST" />
      
      <response name = "qos-ok" />
      
      <field name = "prefetch-size" domain = "long" label = "prefetch window in octets">
        <doc>
          The client can request that messages be sent in advance so that when the client
          finishes processing a message, the following message is already held locally,
          rather than needing to be sent down the channel. Prefetching gives a performance
          improvement. This field specifies the prefetch window size in octets. May be set
          to zero, meaning "no specific limit". Note that other prefetch limits may still
          apply.
        </doc>
      </field>
      
      <field name = "prefetch-count" domain = "short" label = "prefetch window in messages">
        <doc>
          Specifies a prefetch window in terms of whole messages. This field may be used
          in combination with the prefetch-size field; a message will only be sent in
          advance if both prefetch windows (and those at the channel and connection level)
          allow it.
        </doc>
      </field>
      
      <field name = "consume-rate" domain = "long" label = "transfer rate in octets/second">
        <doc>
          Specifies a desired transfer rate in octets per second. This is usually
          determined by the application that uses the streaming data. A value of zero
          means "no limit", i.e. as rapidly as possible.
        </doc>

        <rule name = "01">
          <!-- TODO: Rule split? -->
          <doc>
            The server MAY ignore the prefetch values and consume rates, depending on
            the type of stream and the ability of the server to queue and/or reply it.
            The server MAY drop low-priority messages in favour of high-priority
            messages.
          </doc>
        </rule>
      </field>
      
      <field name = "global" domain = "bit" label = "apply to entire connection">
        <doc>
          By default the QoS settings apply to the current channel only. If this field is
          set, they are applied to the entire connection.
        </doc>
      </field>
    </method>
    
    <method name = "qos-ok" synchronous = "1" index = "11" label = "confirm the requested qos">
      <doc>
        This method tells the client that the requested QoS levels could be handled by the
        server. The requested QoS applies to all active consumers until a new QoS is
        defined.
      </doc>
      
      <chassis name = "client" implement = "MUST" />
    </method>
    
    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->
    
    <method name = "consume" synchronous = "1" index = "20" label = "start a queue consumer">
      <doc>
        This method asks the server to start a "consumer", which is a transient request for
        messages from a specific queue. Consumers last as long as the channel they were
        created on, or until the client cancels them.
      </doc>

      <rule name = "01">
        <doc>
          The server SHOULD support at least 16 consumers per queue, unless the queue was
          declared as private, and ideally, impose no limit except as defined by available
          resources.
        </doc>
      </rule>

      <rule name = "02">
        <doc>
          Streaming applications SHOULD use different channels to select different
          streaming resolutions. AMQP makes no provision for filtering and/or transforming
          streams except on the basis of priority-based selective delivery of individual
          messages.
        </doc>
      </rule>

      <chassis name = "server" implement = "MUST" />
      <response name = "consume-ok" />

      <field name = "ticket" domain = "access-ticket">
        <rule name = "01">
          <doc>
            The client MUST provide a valid access ticket giving "read" access rights to
            the realm for the queue.
          </doc>
        </rule>
      </field>

      <field name = "queue" domain = "queue-name">
        <doc>
          Specifies the name of the queue to consume from. If the queue name is null,
          refers to the current queue for the channel, which is the last declared queue.
        </doc>

        <rule name = "01">
          <doc>
            If the client did not previously declare a queue, and the queue name in this
            method is empty, the server MUST raise a connection exception with reply
            code 530 (not allowed).
          </doc>
        </rule>
      </field>

      <field name = "consumer-tag" domain = "consumer-tag">
        <doc>
          Specifies the identifier for the consumer. The consumer tag is local to a
          connection, so two clients can use the same consumer tags. If this field is
          empty the server will generate a unique tag.
        </doc>

        <rule name = "01">
          <!-- TODO: Rule split? -->
          <doc>
            The tag MUST NOT refer to an existing consumer. If the client attempts to
            create two consumers with the same non-empty tag the server MUST raise a
            connection exception with reply code 530 (not allowed).
          </doc>
        </rule>
      </field>

      <field name = "no-local" domain = "no-local" />

      <field name = "exclusive" domain = "bit" label = "request exclusive access">
        <doc>
          Request exclusive consumer access, meaning only this consumer can access the
          queue.
        </doc>


        <!-- Rule test name: was "amq_file_00" -->    
        <rule name = "01">
          <doc>
            If the server cannot grant exclusive access to the queue when asked, -
            because there are other consumers active - it MUST raise a channel exception
            with return code 405 (resource locked).
          </doc>
        </rule>
      </field>

      <field name = "nowait" domain = "bit" label = "do not send a reply method">
        <doc>
          If set, the server will not respond to the method. The client should not wait
          for a reply method. If the server could not complete the method it will raise a
          channel or connection exception.
        </doc>
      </field>
      
      <field name = "filter" domain = "table" label = "arguments for consuming">
      	<doc>
          A set of filters for the consume. The syntax and semantics
		  of these filters depends on the providers implementation.
        </doc>
      </field>
    </method>

    <method name = "consume-ok" synchronous = "1" index = "21" label = "confirm a new consumer">
      <doc>
        This method provides the client with a consumer tag which it may use in methods that
        work with the consumer.
      </doc>

      <chassis name = "client" implement = "MUST" />

      <field name = "consumer-tag" domain = "consumer-tag">
        <doc>Holds the consumer tag specified by the client or provided by the server.</doc>
      </field>
    </method>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "cancel" synchronous = "1" index = "30" label = "end a queue consumer">
      <doc>
        This method cancels a consumer. Since message delivery is asynchronous the client
        may continue to receive messages for a short while after cancelling a consumer. It
        may process or discard these as appropriate.
      </doc>

      <chassis name = "server" implement = "MUST" />

      <response name = "cancel-ok" />

      <field name = "consumer-tag" domain = "consumer-tag" />

      <field name = "nowait" domain = "bit" label = "do not send a reply method">
        <doc>
          If set, the server will not respond to the method. The client should not wait
          for a reply method. If the server could not complete the method it will raise a
          channel or connection exception.
        </doc>
      </field>
    </method>

    <method name = "cancel-ok" synchronous = "1" index = "31" label = "confirm a cancelled consumer">
      <doc>This method confirms that the cancellation was completed.</doc>

      <chassis name = "client" implement = "MUST" />

      <field name = "consumer-tag" domain = "consumer-tag" />
    </method>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "publish" content = "1" index = "40" label = "publish a message">
      <doc>
        This method publishes a message to a specific exchange. The message will be routed
        to queues as defined by the exchange configuration and distributed to any active
        consumers as appropriate.
      </doc>

      <chassis name = "server" implement = "MUST" />

      <field name = "ticket" domain = "access-ticket">
        <rule name = "01">
          <doc>
            The client MUST provide a valid access ticket giving "write" access rights
            to the access realm for the exchange.
          </doc>
        </rule>
      </field>

      <field name = "exchange" domain = "exchange-name">
        <doc>
          Specifies the name of the exchange to publish to. The exchange name can be
          empty, meaning the default exchange. If the exchange name is specified, and that
          exchange does not exist, the server will raise a channel exception.
        </doc>

        <rule name = "01">
          <doc>
            The server MUST accept a blank exchange name to mean the default exchange.
          </doc>
        </rule>

        <rule name = "02">
          <doc>
            If the exchange was declared as an internal exchange, the server MUST
            respond with a reply code 403 (access refused) and raise a channel
            exception.
          </doc>
        </rule>

        <rule name = "03">
          <doc>
            The exchange MAY refuse stream content in which case it MUST respond with a
            reply code 540 (not implemented) and raise a channel exception.
          </doc>
        </rule>
      </field>

      <field name = "routing-key" domain = "shortstr" label = "Message routing key">
        <doc>
          Specifies the routing key for the message. The routing key is used for routing
          messages depending on the exchange configuration.
        </doc>
      </field>

      <field name = "mandatory" domain = "bit" label = "indicate mandatory routing">
        <doc>
          This flag tells the server how to react if the message cannot be routed to a
          queue. If this flag is set, the server will return an unroutable message with a
          Return method. If this flag is zero, the server silently drops the message.
        </doc>

        <!-- Rule test name: was "amq_stream_00" -->    
        <rule name = "01">
          <doc>The server SHOULD implement the mandatory flag.</doc>
        </rule>
      </field>

      <field name = "immediate" domain = "bit" label = "request immediate delivery">
        <doc>
          This flag tells the server how to react if the message cannot be routed to a
          queue consumer immediately. If this flag is set, the server will return an
          undeliverable message with a Return method. If this flag is zero, the server
          will queue the message, but with no guarantee that it will ever be consumed.
        </doc>

        <!-- Rule test name: was "amq_stream_00" -->    
        <rule name = "01">
          <doc>The server SHOULD implement the immediate flag.</doc>
        </rule>
      </field>
    </method>

    <method name = "return" content = "1" index = "50" label = "return a failed message">
      <doc>
        This method returns an undeliverable message that was published with the "immediate"
        flag set, or an unroutable message published with the "mandatory" flag set. The
        reply code and text provide information about the reason that the message was
        undeliverable.
      </doc>

      <chassis name = "client" implement = "MUST" />

      <field name = "reply-code" domain = "reply-code" />

      <field name = "reply-text" domain = "reply-text" />

      <field name = "exchange" domain = "exchange-name">
        <doc>
          Specifies the name of the exchange that the message was originally published to.
        </doc>
      </field>

      <field name = "routing-key" domain = "shortstr" label = "Message routing key">
        <doc>Specifies the routing key name specified when the message was published.</doc>
      </field>
    </method>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "deliver" content = "1" index = "60"
      label = "notify the client of a consumer message">
      <doc>
        This method delivers a message to the client, via a consumer. In the asynchronous
        message delivery model, the client starts a consumer using the Consume method, then
        the server responds with Deliver methods as and when messages arrive for that
        consumer.
      </doc>

      <chassis name = "client" implement = "MUST" />

      <field name = "consumer-tag" domain = "consumer-tag" />

      <field name = "delivery-tag" domain = "delivery-tag" />

      <field name = "exchange" domain = "exchange-name">
        <doc>
          Specifies the name of the exchange that the message was originally published to.
        </doc>
      </field>

      <field name = "queue" domain = "queue-name">
        <doc>
          Specifies the name of the queue that the message came from. Note that a single
          channel can start many consumers on different queues.
        </doc>
        <assert check = "notnull" />
      </field>
    </method>
  </class>

  <!-- ==  TX  =============================================================== -->

  <class name = "tx" handler = "channel" index = "90" label = "work with standard transactions">
    <doc>
      Standard transactions provide so-called "1.5 phase commit". We can ensure that work is
      never lost, but there is a chance of confirmations being lost, so that messages may be
      resent. Applications that use standard transactions must be able to detect and ignore
      duplicate messages.
    </doc>

    <!-- TODO: Rule split? -->

    <rule name = "01">
      <doc>
        An client using standard transactions SHOULD be able to track all messages received
        within a reasonable period, and thus detect and reject duplicates of the same
        message. It SHOULD NOT pass these to the application layer.
      </doc>
    </rule>

    <doc type = "grammar">
      tx                  = C:SELECT S:SELECT-OK
                          / C:COMMIT S:COMMIT-OK
                          / C:ROLLBACK S:ROLLBACK-OK
    </doc>

    <chassis name = "server" implement = "SHOULD" />
    <chassis name = "client" implement = "MAY" />

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "select" synchronous = "1" index = "10" label = "select standard transaction mode">
      <doc>
        This method sets the channel to use standard transactions. The client must use this
        method at least once on a channel before using the Commit or Rollback methods.
      </doc>
      <chassis name = "server" implement = "MUST" />
      <response name = "select-ok" />
    </method>

    <method name = "select-ok" synchronous = "1" index = "11" label = "confirm transaction mode">
      <doc>
        This method confirms to the client that the channel was successfully set to use
        standard transactions.
      </doc>
      <chassis name = "client" implement = "MUST" />
    </method>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "commit" synchronous = "1" index = "20" label = "commit the current transaction">
      <doc>
        This method commits all messages published and acknowledged in the current
        transaction. A new transaction starts immediately after a commit.
      </doc>
      <chassis name = "server" implement = "MUST" />
      <response name = "commit-ok" />
    </method>

    <method name = "commit-ok" synchronous = "1" index = "21" label = "confirm a successful commit">
      <doc>
        This method confirms to the client that the commit succeeded. Note that if a commit
        fails, the server raises a channel exception.
      </doc>
      <chassis name = "client" implement = "MUST" />
    </method>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "rollback" synchronous = "1" index = "30"
      label = "abandon the current transaction">
      <doc>
        This method abandons all messages published and acknowledged in the current
        transaction. A new transaction starts immediately after a rollback.
      </doc>
      <chassis name = "server" implement = "MUST" />
      <response name = "rollback-ok" />
    </method>

    <method name = "rollback-ok" synchronous = "1" index = "31" label = "confirm successful rollback">
      <doc>
        This method confirms to the client that the rollback succeeded. Note that if an
        rollback fails, the server raises a channel exception.
      </doc>
      <chassis name = "client" implement = "MUST" />
    </method>
  </class>

  <!-- ==  DTX  ============================================================== -->

  <class name = "dtx" handler = "channel" index = "100" label = "work with distributed transactions">
    <doc>
      Distributed transactions provide so-called "2-phase commit". The AMQP distributed
      transaction model supports the X-Open XA architecture and other distributed transaction
      implementations. The Dtx class assumes that the server has a private communications
      channel (not AMQP) to a distributed transaction coordinator.
    </doc>
    
    <doc type = "grammar">
      dtx                 = C:SELECT S:SELECT-OK
                            C:START S:START-OK
    </doc>

    <chassis name = "server" implement = "MAY" />
    <chassis name = "client" implement = "MAY" />

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "select" synchronous = "1" index = "10" label = "select standard transaction mode">
      <doc>
        This method sets the channel to use distributed transactions. The client must use
        this method at least once on a channel before using the Start method.
      </doc>
      <chassis name = "server" implement = "MUST" />
      <response name = "select-ok" />
    </method>

    <method name = "select-ok" synchronous = "1" index = "11" label = "confirm transaction mode">
      <doc>
        This method confirms to the client that the channel was successfully set to use
        distributed transactions.
      </doc>
      <chassis name = "client" implement = "MUST" />
    </method>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "start" synchronous = "1" index = "20"
      label = "start a new distributed transaction">
      <doc>
        This method starts a new distributed transaction. This must be the first method on a
        new channel that uses the distributed transaction mode, before any methods that
        publish or consume messages.
      </doc>
      <chassis name = "server" implement = "MAY" />
      <response name = "start-ok" />
      <field name = "dtx-identifier" domain = "shortstr" label = "transaction identifier">
        <doc>
          The distributed transaction key. This identifies the transaction so that the
          AMQP server can coordinate with the distributed transaction coordinator.
        </doc>
        <assert check = "notnull" />
      </field>
    </method>

    <method name = "start-ok" synchronous = "1" index = "21"
      label = "confirm the start of a new distributed transaction">
      <doc>
        This method confirms to the client that the transaction started. Note that if a
        start fails, the server raises a channel exception.
      </doc>
      <chassis name = "client" implement = "MUST" />
    </method>
  </class>

  <!-- ==  TUNNEL  =========================================================== -->

  <class name = "tunnel" handler = "tunnel" index = "110" label = "methods for protocol tunnelling">
    <doc>
      The tunnel methods are used to send blocks of binary data - which can be serialised AMQP
      methods or other protocol frames - between AMQP peers.
    </doc>

    <doc type = "grammar">
      tunnel              = C:REQUEST
                          / S:REQUEST
    </doc>

    <chassis name = "server" implement = "MAY" />
    <chassis name = "client" implement = "MAY" />

    <field name = "headers"     domain = "table"      label = "message header field table" />
    <field name = "proxy-name"  domain = "shortstr"   label = "identity of tunnelling proxy" />
    <field name = "data-name"   domain = "shortstr"   label = "name or type of message being tunnelled" />
    <field name = "durable"     domain = "octet"      label = "message durability indicator" />
    <field name = "broadcast"   domain = "octet"      label = "message broadcast mode" />

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "request" content = "1" index = "10" label = "sends a tunnelled method">
      <doc>
        This method tunnels a block of binary data, which can be an encoded
        AMQP method or other data. The binary data is sent as the content for
        the Tunnel.Request method.
      </doc>
      <chassis name = "server" implement = "MUST" />
      <field name = "meta-data" domain = "table" label = "meta data for the tunnelled block">
        <doc>
          This field table holds arbitrary meta-data that the sender needs to
          pass to the recipient.
        </doc>
      </field>
    </method>
  </class>

  <!-- == MESSAGE ============================================================ -->

  <class name = "message" index = "120" handler = "channel" label = "[WORK IN PROGRESS] message transfer">
    <doc>
      [WORK IN PROGRESS] The message class provides methods that support an industry-standard messaging model.
    </doc>

    <doc type = "grammar">
      message             = C:QOS S:OK
                          / C:CONSUME S:OK
                          / C:CANCEL S:OK
                          / C:TRANSFER ( S:OK / S:REJECT )
                          / S:TRANSFER ( C:OK / C:REJECT )
                          / C:GET ( S:OK / S:EMPTY )
                          / C:RECOVER S:OK
                          / C:OPEN S:OK
                          / S:OPEN C:OK
                          / C:APPEND S:OK
                          / S:APPEND C:OK
                          / C:CLOSE S:OK
                          / S:CLOSE C:OK
                          / C:CHECKPOINT S:OK
                          / S:CHECKPOINT C:OK
                          / C:RESUME S:OFFSET
                          / S:RESUME C:OFFSET
    </doc>

    <chassis name = "server" implement = "MUST" />
    <chassis name = "client" implement = "MUST" />

    <rule name = "01">
      <doc>
        The server SHOULD respect the persistent property of messages
        and SHOULD make a best-effort to hold persistent mess ages on
        a reliable storage mechanism.
      </doc>
      <doc type = "scenario">
        Send a persistent message to queue, stop server, restart
        server and then verify whether message is still present.
        Assumes that queues are durable. Persistence without durable
        queues makes no sense.
      </doc>
    </rule>

    <rule name = "02">
      <doc>
        The server MUST NOT discard a persistent message in case of a
        queue overflow.
      </doc>
      <doc type = "scenario">
        Create a queue overflow situation with persistent messages and
        verify that messages do not get lost (presumably the server
        will write them to disk).
      </doc>
    </rule>

    <rule name = "03">
      <doc>
        The server MAY use the Channel.Flow method to slow or stop a
        message publisher when necessary.
      </doc>
      <doc type = "scenario">
        Create a queue overflow situation with non-persistent messages
        and verify whether the server responds with Channel.Flow or
        not. Repeat with persistent messages.
      </doc>
    </rule>

    <rule name = "04">
      <doc>
        The server MAY overflow non-persistent messages to persistent
        storage.
      </doc>
    </rule>

    <rule name = "05">
      <doc>
        The server MAY discard or dead-letter non-persistent messages
        on a priority basis if the queue size exceeds some configured
        limit.
      </doc>
    </rule>

    <rule name = "06">
      <doc>
        The server MUST implement at least 2 priority levels for
        messages, where priorities 0-4 and 5-9 are treated as two
        distinct levels.
      </doc>
      <doc type = "scenario">
        Send a number of priority 0 messages to a queue. Send one
        priority 9 message. Consume messages from the queue and verify
        that the first message received was priority 9.
      </doc>
    </rule>

    <rule name = "07">
      <doc>
        The server MAY implement up to 10 priority levels.
      </doc>
      <doc type = "scenario">
        Send a number of messages with mixed priorities to a queue, so
        that all priority values from 0 to 9 are exercised. A good
        scenario would be ten messages in low-to-high priority.
        Consume from queue and verify how many priority levels emerge.
      </doc>
    </rule>

    <rule name = "08">
      <doc>
        The server MUST deliver messages of the same priority in order
        irrespective of their individual persistence.
      </doc>
      <doc type = "scenario">
        Send a set of messages with the same priority but different
        persistence settings to a queue. Consume and verify that
        messages arrive in same order as originally published.
      </doc>
    </rule>

    <rule name = "09">
      <doc>
        The server MUST support automatic acknowledgements on
        messages, i.e. consumers with the no-ack field set to FALSE.
      </doc>
      <doc type = "scenario">
        Create a queue and a consumer using automatic
        acknowledgements. Publish a set of messages to the queue.
        Consume the messages and verify that all messages are
        received.
      </doc>
    </rule>

    <rule name = "10">
      <doc>
        The server MUST support explicit acknowledgements on messages,
        i.e. consumers with the no-ack field set to TRUE.
      </doc>
      <doc type = "scenario">
        Create a queue and a consumer using explicit acknowledgements.
        Publish a set of messages to the queue. Consume the messages
        but acknowledge only half of them. Disconnect and reconnect,
        and consume from the queue. Verify that the remaining messages
        are received.
      </doc>
    </rule>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "transfer" index = "10" label = "[WORK IN PROGRESS] transfer a message">
      <doc>
        [WORK IN PROGRESS] This method transfers a message between two peers. When a
        client uses this method to publish a message to a broker, the
        destination identifies a specific exchange. The message will
        then be routed to queues as defined by the exchange
        configuration and distributed to any active consumers when the
        transaction, if any, is committed.

        In the asynchronous message delivery model, the client starts
        a consumer using the Consume method and passing in a
        destination, then the broker responds with transfer methods to
        the specified destination as and when messages arrive for that
        consumer.

        If synchronous message delivery is required, the client may
        issue a get request which on success causes a single message
        to be transferred to the specified destination.

        Message acknowledgement is signalled by the return result of
        this method.
      </doc>

      <rule name = "01">
        <doc>
          The recipient MUST NOT return ok before the message has been
          processed as defined by the QoS settings.
        </doc>
      </rule>

      <chassis name = "server" implement = "MUST" />
      <chassis name = "client" implement = "MUST" />
      <response name = "ok" />
      <response name = "reject" />

      <field name = "ticket"      domain = "access-ticket">
        <rule name = "01">
          <doc>
            The client MUST provide a valid access ticket giving "write" access rights
            to the access realm for the exchange.
          </doc>
        </rule>
      </field>

      <field name = "destination" domain = "destination">
        <doc>
          Specifies the destination to which the message is to be
          transferred. The destination can be empty, meaning the
          default exchange or consumer. If the destination is
          specified, and that exchange or consumer does not exist, the
          peer must raise a channel exception.
        </doc>

        <rule name = "01">
          <doc>
            The server MUST accept a blank destination to mean the
            default exchange.
          </doc>
        </rule>

        <rule name = "02">
          <doc>
            If the destination refers to an internal exchange, the
            server MUST raise a channel exception with a reply code
            403 (access refused).
          </doc>
        </rule>

        <rule name = "03">
          <doc>
            A destination MAY refuse message content in which case it
            MUST raise a channel exception with reply code 540 (not
            implemented).
          </doc>
        </rule>
      </field>

      <field name = "redelivered" domain = "redelivered" />

      <field name = "immediate"   domain = "bit"         label = "request immediate delivery">
        <doc>
          This flag tells the server how to react if the message
          cannot be routed to a queue consumer immediately. If this
          flag is set, the server will reject the message. If this
          flag is zero, the server will queue the message, but with no
          guarantee that it will ever be consumed.
        </doc>
        <rule name = "01">
          <doc>
            The server SHOULD implement the immediate flag.
          </doc>
        </rule>
      </field>

      <field name = "ttl"         domain = "duration"    label = "time to live">
        <doc>
          If this is set to a non zero value then a message expiration
          time will be computed based on the current time plus this
          value. Messages that live longer than their expiration time
          will be discarded (or dead lettered).
        </doc>
        <rule name = "01">
          <doc>
            If a message is transfered between brokers before delivery
            to a final consumer the ttl should be decremented before
            peer to peer transfer and both timestamp and expiration
            should be cleared.
          </doc>
        </rule>
      </field>

      <!-- begin headers -->
      <field name = "priority"            domain = "octet"         label = "message priority, 0 to 9" />
      <field name = "timestamp"           domain = "timestamp"     label = "message timestamp">
        <doc>
          Set on arrival by the broker.
        </doc>
      </field>
      <field name = "delivery-mode"       domain = "octet"         label = "non-persistent (1) or persistent (2)" />
      <field name = "expiration"          domain = "timestamp"     label = "message expiration time">
        <doc>
          The expiration header assigned by the broker. After
          receiving the message the broker sets expiration to the sum
          of the ttl specified in the publish method and the current
          time. (ttl = expiration - timestamp)
        </doc>
      </field>
      <field name = "exchange"            domain = "exchange-name" label = "originating exchange" />
      <field name = "routing-key"         domain = "shortstr"      label = "message routing key" />
      <field name = "message-id"          domain = "shortstr"      label = "application message identifier" />
      <field name = "correlation-id"      domain = "shortstr"      label = "application correlation identifier" />
      <field name = "reply-to"            domain = "shortstr"      label = "destination to reply to" />
      <field name = "content-type"        domain = "shortstr"      label = "MIME content type" />
      <field name = "content-encoding"    domain = "shortstr"      label = "MIME content encoding" />
      <field name = "user-id"             domain = "shortstr"      label = "creating user id" />
      <field name = "app-id"              domain = "shortstr"      label = "creating application id" />
      <field name = "transaction-id"      domain = "shortstr"      label = "distributed transaction id" />
      <field name = "security-token"      domain = "security-token" />
      <field name = "application-headers" domain = "table"         label = "application specific headers table" />
      <!-- end headers -->

      <field name = "body" domain = "content" label = "message body" />
    </method>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "consume" index = "20" label = "[WORK IN PROGRESS] start a queue consumer">
      <doc>
        [WORK IN PROGRESS] This method asks the server to start a "consumer", which is a transient request for
        messages from a specific queue. Consumers last as long as the channel they were
        created on, or until the client cancels them.
      </doc>

      <rule name = "01">
        <doc>
          The server SHOULD support at least 16 consumers per queue, and ideally, impose
          no limit except as defined by available resources.
        </doc>
        <doc type = "scenario">
          Create a queue and create consumers on that queue until the server closes the
          connection. Verify that the number of consumers created was at least sixteen
          and report the total number.
        </doc>
      </rule>

      <chassis name = "server" implement = "MUST" />
      <response name = "ok" />

      <field name = "ticket"      domain = "access-ticket">
        <rule name = "01" on-failure = "access-refused">
          <doc>
            The client MUST provide a valid access ticket giving "read" access rights to
            the realm for the queue.
          </doc>
          <doc type = "scenario">
            Attempt to create a consumer with an invalid (non-zero) access ticket.
          </doc>
        </rule>
      </field>

      <field name = "queue"       domain = "queue-name">
        <doc>
          Specifies the name of the queue to consume from. If the queue name is null,
          refers to the current queue for the channel, which is the last declared queue.
        </doc>
        <rule name = "01" on-failure = "not-allowed">
          <doc>
            If the queue name is empty the client MUST have previously declared a
            queue using this channel.
          </doc>
          <doc type = "scenario">
            Attempt to create a consumer with an empty queue name and no previously
            declared queue on the channel.
          </doc>
        </rule>
      </field>

      <field name = "destination" domain = "destination" label = "incoming message destination">
        <doc>
          Specifies the destination for the consumer. The destination is local to a
          connection, so two clients can use the same destination.
        </doc>
        <rule name = "01" on-failure = "not-allowed">
          <doc>
            The client MUST NOT specify a destination that refers to an existing consumer.
          </doc>
          <doc type = "scenario">
            Attempt to create two consumers with the same non-empty destination.
          </doc>
        </rule>
        <rule name = "02" on-failure = "not-allowed">
          <doc>
            The destination is valid only within the channel from which the
            consumer was created. I.e. a client MUST NOT create a consumer in one
            channel and then use it in another.
          </doc>
          <doc type = "scenario">
            Attempt to create a consumer in one channel, then use in another channel,
            in which consumers have also been created (to test that the server uses
            unique destinations).
          </doc>
        </rule>
      </field>

      <field name = "no-local"    domain = "no-local" />

      <field name = "no-ack"      domain = "no-ack" />

      <field name = "exclusive"   domain = "bit"         label = "request exclusive access">
        <doc>
          Request exclusive consumer access, meaning only this consumer can access the
          queue.
        </doc>

        <rule name = "01" on-failure = "access-refused">
          <doc>
            The client MAY NOT gain exclusive access to a queue that already has
            active consumers.
          </doc>
          <doc type = "scenario">
            Open two connections to a server, and in one connection create a shared
            (non-exclusive) queue and then consume from the queue.  In the second
            connection attempt to consume from the same queue using the exclusive
            option.
          </doc>
        </rule>
      </field>
      
      <field name = "filter" domain = "table" label = "arguments for consuming">
      	<doc>
          A set of filters for the consume. The syntax and semantics
		  of these filters depends on the providers implementation.
        </doc>
      </field>
    </method>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "cancel" index = "30" label = "[WORK IN PROGRESS] end a queue consumer">
      <doc>
        [WORK IN PROGRESS] This method cancels a consumer. This does not affect already delivered
        messages, but it does mean the server will not send any more messages for
        that consumer. The client may receive an arbitrary number of messages in
        between sending the cancel method and receiving the cancel-ok reply.
      </doc>

      <rule name = "01">
        <doc>
          If the queue does not exist the server MUST ignore the cancel method, so
          long as the consumer tag is valid for that channel.
        </doc>
      </rule>

      <chassis name = "server" implement = "MUST" />
      <response name = "ok" />

      <field name = "destination" domain = "destination"/>
    </method>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "get" index = "40" label = "[WORK IN PROGRESS] direct access to a queue">
      <doc>
        [WORK IN PROGRESS] This method provides a direct access to the messages in a queue using a synchronous
        dialogue that is designed for specific types of application where synchronous
        functionality is more important than performance.
      </doc>

      <response name = "ok" />
      <response name = "empty" />
      <chassis name = "server" implement = "MUST" />

      <field name = "ticket" domain = "access-ticket">
        <rule name = "01">
          <doc>
            The client MUST provide a valid access ticket giving "read" access rights to
            the realm for the queue.
          </doc>
        </rule>
      </field>
      <field name = "queue" domain = "queue-name">
        <doc>
          Specifies the name of the queue to consume from. If the queue name is null,
          refers to the current queue for the channel, which is the last declared queue.
        </doc>
        <rule name = "01">
          <doc>
            If the client did not previously declare a queue, and the queue name in this
            method is empty, the server MUST raise a connection exception with reply
            code 530 (not allowed).
          </doc>
        </rule>
      </field>

      <field name = "destination" domain = "destination">
        <doc>
          On normal completion of the get request (i.e. a response of
          ok). A message will be transferred to the supplied destination.
        </doc>
      </field>

      <field name = "no-ack" domain = "no-ack" />
    </method>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "recover" index = "50" label = "[WORK IN PROGRESS] redeliver unacknowledged messages">
      <doc>
        [WORK IN PROGRESS] This method asks the broker to redeliver all unacknowledged
        messages on a specified channel. Zero or more messages may be
        redelivered. This method is only allowed on non-transacted
        channels.
      </doc>

      <rule name = "01">
        <doc>
          The server MUST set the redelivered flag on all messages
          that are resent.
        </doc>
      </rule>

      <rule name = "02">
        <doc>
          The server MUST raise a channel exception if this is called
          on a transacted channel.
        </doc>
      </rule>

      <chassis name = "server" implement = "MUST" />
      <response name = "ok" />

      <field name = "requeue" domain = "bit" label = "requeue the message">
        <doc>
          If this field is zero, the message will be redelivered to
          the original recipient. If this bit is 1, the server will
          attempt to requeue the message, potentially then delivering
          it to an alternative subscriber.
        </doc>
      </field>
    </method>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "open" index = "60" label = "[WORK IN PROGRESS] create a reference to an empty message body">
      <doc>
        [WORK IN PROGRESS] This method creates a reference. A references provides a means
        to send a message body into a temporary area at the recipient
        end and then deliver the message by referring to this
        temporary area. This is how the protocol handles large message
        transfers.

        The scope of a ref is defined to be between calls to
        open (or resume) and close. Between these points it is valid
        for a ref to be used from any content data type, and so the
        receiver must hold onto its contents. Should the channel be
        closed when a ref is still in scope, the receiver may discard
        its contents (unless it is checkpointed). A ref that is in
        scope is considered open.
      </doc>

      <chassis name = "server" implement = "MUST" />
      <chassis name = "client" implement = "MUST" />
      <response name = "ok" />

      <field name = "reference" domain = "reference">
        <rule name = "01">
          <doc>
            The recipient MUST generate an error if the reference is
            currently open (in scope).
          </doc>
        </rule>
      </field>
    </method>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "close" index = "70" label = "[WORK IN PROGRESS] close a reference">
      <doc>
        [WORK IN PROGRESS] This method signals the recipient that no more data will be
        appended to the reference.
      </doc>

      <rule name = "01">
        <doc>
          A recipient CANNOT acknowledge a message until its reference
          is closed (not in scope).
        </doc>
      </rule>

      <chassis name = "server" implement = "MUST" />
      <chassis name = "client" implement = "MUST" />

      <response name = "ok" />
      <field name = "reference" domain = "reference" label = "target reference">
        <rule name = "01">
          <doc>
            The recipient MUST generate an error if the reference was
            not previously open (in scope).
          </doc>
        </rule>
      </field>
    </method>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "append" index = "80" label = "[WORK IN PROGRESS] append to a reference">
      <doc>
        [WORK IN PROGRESS] This method appends data to a reference.
      </doc>

      <chassis name = "server" implement = "MUST" />
      <chassis name = "client" implement = "MUST" />
      <response name = "ok" />

      <field name = "reference" domain = "reference" label = "target reference">
        <rule name = "01">
          <doc>
            The recipient MUST generate an error if the reference is
            not open (not in scope).
          </doc>
        </rule>
      </field>
      <field name = "bytes"     domain = "longstr"   label = "data to append" />
    </method>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "checkpoint" index = "90" label = "[WORK IN PROGRESS] checkpoint a message body">
      <doc>
        [WORK IN PROGRESS] This method provides a means to checkpoint large message
        transfer. The sender may ask the recipient to checkpoint the
        contents of a reference using the supplied identifier. The
        sender may then resume the transfer at a later point. It is at
        the discretion of the recipient how much data to save with the
        checkpoint, and the sender MUST honour the offset returned by
        the resume method.
      </doc>

      <chassis name = "server" implement = "MUST" />
      <chassis name = "client" implement = "MUST" />
      <response name = "ok" />

      <field name = "reference"  domain = "reference" label = "target reference">
        <rule name = "01">
          <doc>
            The recipient MUST generate an error if the reference is
            not open (not in scope).
          </doc>
        </rule>
      </field>
      <field name = "identifier" domain = "shortstr"  label = "checkpoint identifier">
        <doc>
          This is the checkpoint identifier. This is an arbitrary
          string chosen by the sender. For checkpointing to work
          correctly the sender must use the same checkpoint identifier
          when resuming the message. A good choice for the checkpoint
          identifier would be the SHA1 hash of the message properties
          data (including the original filename, revised time, etc.).
        </doc>
      </field>
    </method>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "resume" index = "100" label = "[WORK IN PROGRESS] open and resume a checkpointed message">
      <doc>
        [WORK IN PROGRESS] This method resumes a reference from the last checkpoint. A
        reference is considered to be open (in scope) after a resume
        even though it will not have been opened via the open method
        during this session.
      </doc>

      <chassis name = "server" implement = "MUST" />
      <chassis name = "client" implement = "MUST" />
      <response name = "offset" />

      <field name = "reference"  domain = "reference" label = "target reference">
        <rule name = "01">
          <doc>
            The recipient MUST generate an error if the reference is
            currently open (in scope).
          </doc>
        </rule>
      </field>
      <field name = "identifier" domain = "shortstr"  label = "checkpoint identifier" />
    </method>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->

    <method name = "qos" index = "110" label = "[WORK IN PROGRESS] specify quality of service">
      <doc>
        [WORK IN PROGRESS] This method requests a specific quality of service. The QoS can be specified for the
        current channel or for all channels on the connection. The particular properties and
        semantics of a qos method always depend on the content class semantics. Though the
        qos method could in principle apply to both peers, it is currently meaningful only
        for the server.
      </doc>

      <chassis name = "server" implement = "MUST" />
      <response name = "ok" />

      <field name = "prefetch-size" domain = "long" label = "prefetch window in octets">
        <doc>
          The client can request that messages be sent in advance so that when the client
          finishes processing a message, the following message is already held locally,
          rather than needing to be sent down the channel. Prefetching gives a performance
          improvement. This field specifies the prefetch window size in octets. The server
          will send a message in advance if it is equal to or smaller in size than the
          available prefetch size (and also falls into other prefetch limits). May be set
          to zero, meaning "no specific limit", although other prefetch limits may still
          apply. The prefetch-size is ignored if the no-ack option is set.
        </doc>
        <rule name = "01">
          <doc>
            The server MUST ignore this setting when the client is not processing any
            messages - i.e. the prefetch size does not limit the transfer of single
            messages to a client, only the sending in advance of more messages while
            the client still has one or more unacknowledged messages.
          </doc>
          <doc type = "scenario">
            Define a QoS prefetch-size limit and send a single message that exceeds
            that limit.  Verify that the message arrives correctly.
          </doc>
        </rule>
      </field>

      <field name = "prefetch-count" domain = "short" label = "prefetch window in messages">
        <doc>
          Specifies a prefetch window in terms of whole messages. This field may be used
          in combination with the prefetch-size field; a message will only be sent in
          advance if both prefetch windows (and those at the channel and connection level)
          allow it. The prefetch-count is ignored if the no-ack option is set.
        </doc>
        <rule name = "01">
          <doc>
            The server may send less data in advance than allowed by the client's
            specified prefetch windows but it MUST NOT send more.
          </doc>
          <doc type = "scenario">
            Define a QoS prefetch-size limit and a prefetch-count limit greater than
            one.  Send multiple messages that exceed the prefetch size.  Verify that
            no more than one message arrives at once.
          </doc>
        </rule>
      </field>

      <field name = "global" domain = "bit" label = "apply to entire connection">
        <doc>
          By default the QoS settings apply to the current channel only. If this field is
          set, they are applied to the entire connection.
        </doc>
      </field>
    </method>

    <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->
    <!-- === Responses === -->
    
    <method name = "ok" index = "500" label = "[WORK IN PROGRESS] normal completion">
      <doc>
        [WORK IN PROGRESS] Signals the normal completion of a method.
      </doc>
      <chassis name = "server" implement = "MUST" />
      <chassis name = "client" implement = "MUST" />
    </method>

    <method name = "empty" index = "510" label = "[WORK IN PROGRESS] empty queue">
      <doc>
        [WORK IN PROGRESS] Signals that a queue does not contain any messages.
      </doc>
      <chassis name = "server" implement = "MUST" />
      <chassis name = "client" implement = "MUST" />
    </method>

    <method name = "reject" index = "520" label = "[WORK IN PROGRESS] reject a message">
      <doc>
        [WORK IN PROGRESS] This response rejects a message. A message may be rejected for
        a number of reasons.
      </doc>
      <chassis name = "server" implement = "MUST" />
      <chassis name = "client" implement = "MUST" />
      <field name = "code" domain = "reject-code" />
      <field name = "text" domain = "reject-text" />
    </method>

    <method name = "offset" index = "530" label = "[WORK IN PROGRESS] return an offset">
      <doc>
        [WORK IN PROGRESS] Returns the data offset into a reference body.
      </doc>
      <chassis name = "server" implement = "MUST" />
      <chassis name = "client" implement = "MUST" />
      <field name = "value" domain = "offset" label = "offset into a reference body" />
    </method>

  </class>

</amqp>