1 files changed, 37 insertions, 8 deletions
diff --git a/pyasn1/type/opentype.py b/pyasn1/type/opentype.py
index d37a533..29645f0 100644
--- a/pyasn1/type/opentype.py
+++ b/pyasn1/type/opentype.py
@@ -11,11 +11,22 @@ __all__ = ['OpenType']
 class OpenType(object):
     """Create ASN.1 type map indexed by a value
 
-    The *DefinedBy* object models the ASN.1 *DEFINED BY* clause which maps
-    values to ASN.1 types in the context of the ASN.1 SEQUENCE/SET type.
-
-    OpenType objects are duck-type a read-only Python :class:`dict` objects,
-    however the passed `typeMap` is stored by reference.
+    The *OpenType* object models an untyped field of a constructed ASN.1
+    type. In ASN.1 syntax it is usually represented by the
+    `ANY DEFINED BY` for scalars or `SET OF ANY DEFINED BY`,
+    `SEQUENCE OF ANY DEFINED BY` for container types clauses. Typically
+    used together with :class:`~pyasn1.type.univ.Any` object.
+
+    OpenType objects duck-type a read-only Python :class:`dict` objects,
+    however the passed `typeMap` is not copied, but stored by reference.
+    That means the user can manipulate `typeMap` at run time having this
+    reflected on *OpenType* object behavior.
+
+    The |OpenType| class models an untyped field of a constructed ASN.1
+    type. In ASN.1 syntax it is usually represented by the
+    `ANY DEFINED BY` for scalars or `SET OF ANY DEFINED BY`,
+    `SEQUENCE OF ANY DEFINED BY` for container types clauses. Typically
+    used with :class:`~pyasn1.type.univ.Any` type.
 
     Parameters
     ----------
@@ -28,12 +39,14 @@ class OpenType(object):
 
     Examples
     --------
+
+    For untyped scalars:
+
     .. code-block:: python
 
         openType = OpenType(
-            'id',
-            {1: Integer(),
-             2: OctetString()}
+            'id', {1: Integer(),
+                   2: OctetString()}
         )
         Sequence(
             componentType=NamedTypes(
@@ -41,6 +54,22 @@ class OpenType(object):
                 NamedType('blob', Any(), openType=openType)
             )
         )
+
+    For untyped `SET OF` or `SEQUENCE OF` vectors:
+
+    .. code-block:: python
+
+        openType = OpenType(
+            'id', {1: Integer(),
+                   2: OctetString()}
+        )
+        Sequence(
+            componentType=NamedTypes(
+                NamedType('id', Integer()),
+                NamedType('blob', SetOf(componentType=Any()),
+                          openType=openType)
+            )
+        )
     """
 
     def __init__(self, name, typeMap=None):