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+=head1 NAME
+
+perldelta - what's new for perl5.005
+
+=head1 DESCRIPTION
+
+This document describes differences between the 5.004 release and this one.
+
+=head1 About the new versioning system
+
+Perl is now developed on two tracks: a maintenance track that makes
+small, safe updates to released production versions with emphasis on
+compatibility; and a development track that pursues more aggressive
+evolution.  Maintenance releases (which should be considered production
+quality) have subversion numbers that run from C<1> to C<49>, and
+development releases (which should be considered "alpha" quality) run
+from C<50> to C<99>.
+
+Perl 5.005 is the combined product of the new dual-track development
+scheme.
+
+=head1 Incompatible Changes
+
+=head2 WARNING:  This version is not binary compatible with Perl 5.004.
+
+Starting with Perl 5.004_50 there were many deep and far-reaching changes
+to the language internals.  If you have dynamically loaded extensions
+that you built under perl 5.003 or 5.004, you can continue to use them
+with 5.004, but you will need to rebuild and reinstall those extensions
+to use them 5.005.  See L<INSTALL> for detailed instructions on how to
+upgrade.
+
+=head2 Default installation structure has changed
+
+The new Configure defaults are designed to allow a smooth upgrade from
+5.004 to 5.005, but you should read L<INSTALL> for a detailed
+discussion of the changes in order to adapt them to your system.
+
+=head2 Perl Source Compatibility
+
+When none of the experimental features are enabled, there should be
+very few user-visible Perl source compatibility issues.
+
+If threads are enabled, then some caveats apply. C<@_> and C<$_> become
+lexical variables.  The effect of this should be largely transparent to
+the user, but there are some boundary conditions under which user will
+need to be aware of the issues.  For example, C<local(@_)> results in
+a "Can't localize lexical variable @_ ..." message.  This may be enabled
+in a future version.
+
+Some new keywords have been introduced.  These are generally expected to
+have very little impact on compatibility.  See L<New C<INIT> keyword>,
+L<New C<lock> keyword>, and L<New C<qr//> operator>.
+
+Certain barewords are now reserved.  Use of these will provoke a warning
+if you have asked for them with the C<-w> switch.
+See L<C<our> is now a reserved word>.
+
+=head2 C Source Compatibility
+
+There have been a large number of changes in the internals to support
+the new features in this release.
+
+=over 4
+
+=item Core sources now require ANSI C compiler
+
+An ANSI C compiler is now B<required> to build perl.  See F<INSTALL>.
+
+=item All Perl global variables must now be referenced with an explicit prefix
+
+All Perl global variables that are visible for use by extensions now
+have a C<PL_> prefix.  New extensions should C<not> refer to perl globals
+by their unqualified names.  To preserve sanity, we provide limited
+backward compatibility for globals that are being widely used like
+C<sv_undef> and C<na> (which should now be written as C<PL_sv_undef>,
+C<PL_na> etc.)
+
+If you find that your XS extension does not compile anymore because a
+perl global is not visible, try adding a C<PL_> prefix to the global
+and rebuild.
+
+It is strongly recommended that all functions in the Perl API that don't
+begin with C<perl> be referenced with a C<Perl_> prefix.  The bare function
+names without the C<Perl_> prefix are supported with macros, but this
+support may cease in a future release.
+
+See L<perlguts/API LISTING>.
+
+=item Enabling threads has source compatibility issues
+
+Perl built with threading enabled requires extensions to use the new
+C<dTHR> macro to initialize the handle to access per-thread data.
+If you see a compiler error that talks about the variable C<thr> not
+being declared (when building a module that has XS code),  you need
+to add C<dTHR;> at the beginning of the block that elicited the error.
+
+The API function C<perl_get_sv("@",FALSE)> should be used instead of
+directly accessing perl globals as C<GvSV(errgv)>.  The API call is
+backward compatible with existing perls and provides source compatibility
+with threading is enabled.
+
+See L<API Changes for more information>.
+
+=back
+
+=head2 Binary Compatibility
+
+This version is NOT binary compatible with older versions.  All extensions
+will need to be recompiled.  Further binaries built with threads enabled
+are incompatible with binaries built without.  This should largely be
+transparent to the user, as all binary incompatible configurations have
+their own unique architecture name, and extension binaries get installed at
+unique locations.  This allows coexistence of several configurations in
+the same directory hierarchy.  See F<INSTALL>.
+
+=head2 Security fixes may affect compatibility
+
+A few taint leaks and taint omissions have been corrected.  This may lead
+to "failure" of scripts that used to work with older versions.  Compiling
+with -DINCOMPLETE_TAINTS provides a perl with minimal amounts of changes
+to the tainting behavior.  But note that the resulting perl will have
+known insecurities.
+
+Oneliners with the C<-e> switch do not create temporary files anymore.
+
+=head2 Relaxed new mandatory warnings introduced in 5.004
+
+Many new warnings that were introduced in 5.004 have been made
+optional.  Some of these warnings are still present, but perl's new
+features make them less often a problem.  See L<New Diagnostics>.
+
+=head2 Licensing
+
+Perl has a new Social Contract for contributors.  See F<Porting/Contract>.
+
+The license included in much of the Perl documentation has changed.
+Most of the Perl documentation was previously under the implicit GNU
+General Public License or the Artistic License (at the user's choice).
+Now much of the documentation unambigously states the terms under which
+it may be distributed.  Those terms are in general much less restrictive
+than the GNU GPL.  See L<perl> and the individual perl man pages listed
+therein.
+
+=head1 Core Changes
+
+
+=head2 Threads
+
+WARNING: Threading is considered an B<experimental> feature.  Details of the
+implementation may change without notice.  There are known limitations
+and some bugs.  These are expected to be fixed in future versions.
+
+See L<README.threads>.
+
+=head2 Compiler
+
+WARNING: The Compiler and related tools are considered B<experimental>.
+Features may change without notice, and there are known limitations
+and bugs.  Since the compiler is fully external to perl, the default
+configuration will build and install it.
+
+The Compiler produces three different types of transformations of a
+perl program.  The C backend generates C code that captures perl's state
+just before execution begins.  It eliminates the compile-time overheads
+of the regular perl interpreter, but the run-time performance remains
+comparatively the same.  The CC backend generates optimized C code
+equivalent to the code path at run-time.  The CC backend has greater
+potential for big optimizations, but only a few optimizations are
+implemented currently.  The Bytecode backend generates a platform
+independent bytecode representation of the interpreter's state
+just before execution.  Thus, the Bytecode back end also eliminates
+much of the compilation overhead of the interpreter.
+
+The compiler comes with several valuable utilities.
+
+C<B::Lint> is an experimental module to detect and warn about suspicious
+code, especially the cases that the C<-w> switch does not detect.
+
+C<B::Deparse> can be used to demystify perl code, and understand
+how perl optimizes certain constructs.
+
+C<B::Xref> generates cross reference reports of all definition and use
+of variables, subroutines and formats in a program.
+
+C<B::Showlex> show the lexical variables used by a subroutine or file
+at a glance.
+
+C<perlcc> is a simple frontend for compiling perl.
+
+See C<ext/B/README>, L<B>, and the respective compiler modules.
+
+=head2 Regular Expressions
+
+Perl's regular expression engine has been seriously overhauled, and
+many new constructs are supported.  Several bugs have been fixed.
+
+Here is an itemized summary:
+
+=over 4
+
+=item Many new and improved optimizations
+
+Changes in the RE engine:
+
+	Unneeded nodes removed;
+	Substrings merged together;
+	New types of nodes to process (SUBEXPR)* and similar expressions
+	    quickly, used if the SUBEXPR has no side effects and matches
+	    strings of the same length;
+	Better optimizations by lookup for constant substrings;
+	Better search for constants substrings anchored by $ ;
+
+Changes in Perl code using RE engine:
+
+	More optimizations to s/longer/short/;
+	study() was not working;
+	/blah/ may be optimized to an analogue of index() if $& $` $' not seen;
+	Unneeded copying of matched-against string removed;
+	Only matched part of the string is copying if $` $' were not seen;
+
+=item Many bug fixes
+
+Note that only the major bug fixes are listed here.  See F<Changes> for others.
+
+	Backtracking might not restore start of $3.
+	No feedback if max count for * or + on "complex" subexpression
+	    was reached, similarly (but at compile time) for {3,34567}
+	Primitive restrictions on max count introduced to decrease a 
+	    possibility of a segfault;
+	(ZERO-LENGTH)* could segfault;
+	(ZERO-LENGTH)* was prohibited;
+	Long REs were not allowed;
+	/RE/g could skip matches at the same position after a 
+	  zero-length match;
+
+=item New regular expression constructs
+
+The following new syntax elements are supported:
+
+	(?<=RE)
+	(?<!RE)
+	(?{ CODE })
+	(?i-x)
+	(?i:RE)
+	(?(COND)YES_RE|NO_RE)
+	(?>RE)
+	\z
+
+=item New operator for precompiled regular expressions
+
+See L<New C<qr//> operator>.
+
+=item Other improvements
+
+	Better debugging output (possibly with colors),
+            even from non-debugging Perl;
+	RE engine code now looks like C, not like assembler;
+	Behaviour of RE modifiable by `use re' directive;
+	Improved documentation;
+	Test suite significantly extended;
+	Syntax [:^upper:] etc., reserved inside character classes;
+
+=item Incompatible changes
+
+	(?i) localized inside enclosing group;
+	$( is not interpolated into RE any more;
+	/RE/g may match at the same position (with non-zero length)
+	    after a zero-length match (bug fix).
+
+=back
+
+See L<perlre> and L<perlop>.
+
+=head2   Improved malloc()
+
+See banner at the beginning of C<malloc.c> for details.
+
+=head2 Quicksort is internally implemented
+
+Perl now contains its own highly optimized qsort() routine.  The new qsort()
+is resistant to inconsistent comparison functions, so Perl's C<sort()> will
+not provoke coredumps any more when given poorly written sort subroutines.
+(Some C library C<qsort()>s that were being used before used to have this
+problem.)  In our testing, the new C<qsort()> required the minimal number
+of pair-wise compares on average, among all known C<qsort()> implementations.
+
+See C<perlfunc/sort>.
+
+=head2 Reliable signals
+
+Perl's signal handling is susceptible to random crashes, because signals
+arrive asynchronously, and the Perl runtime is not reentrant at arbitrary
+times.
+
+However, one experimental implementation of reliable signals is available
+when threads are enabled.  See C<Thread::Signal>.  Also see F<INSTALL> for
+how to build a Perl capable of threads.
+
+=head2 Reliable stack pointers
+
+The internals now reallocate the perl stack only at predictable times.
+In particular, magic calls never trigger reallocations of the stack,
+because all reentrancy of the runtime is handled using a "stack of stacks".
+This should improve reliability of cached stack pointers in the internals
+and in XSUBs.
+
+=head2 More generous treatment of carriage returns
+
+Perl used to complain if it encountered literal carriage returns in
+scripts.  Now they are mostly treated like whitespace within program text.
+Inside string literals and here documents, literal carriage returns are
+ignored if they occur paired with newlines, or get interpreted as newlines
+if they stand alone.  This behavior means that literal carriage returns
+in files should be avoided.  You can get the older, more compatible (but
+less generous) behavior by defining the preprocessor symbol
+C<PERL_STRICT_CR> when building perl.  Of course, all this has nothing
+whatever to do with how escapes like C<\r> are handled within strings.
+
+Note that this doesn't somehow magically allow you to keep all text files
+in DOS format.  The generous treatment only applies to files that perl
+itself parses.  If your C compiler doesn't allow carriage returns in
+files, you may still be unable to build modules that need a C compiler.
+
+=head2 Memory leaks
+
+C<substr>, C<pos> and C<vec> don't leak memory anymore when used in lvalue
+context.  Many small leaks that impacted applications that embed multiple
+interpreters have been fixed.
+
+=head2 Better support for multiple interpreters
+
+The build-time option C<-DMULTIPLICITY> has had many of the details
+reworked.  Some previously global variables that should have been
+per-interpreter now are.  With care, this allows interpreters to call
+each other.  See the C<PerlInterp> extension on CPAN.
+
+=head2 Behavior of local() on array and hash elements is now well-defined
+
+See L<perlsub/"Temporary Values via local()">.
+
+=head2 C<%!> is transparently tied to the L<Errno> module
+
+See L<perlvar>, and L<Errno>.
+
+=head2 Pseudo-hashes are supported
+
+See L<perlref>.
+
+=head2 C<EXPR foreach EXPR> is supported
+
+See L<perlsyn>.
+
+=head2 Keywords can be globally overridden
+
+See L<perlsub>.
+
+=head2 C<$^E> is meaningful on Win32
+
+See L<perlvar>.
+
+=head2 C<foreach (1..1000000)> optimized
+
+C<foreach (1..1000000)> is now optimized into a counting loop.  It does
+not try to allocate a 1000000-size list anymore.
+
+=head2 C<Foo::> can be used as implicitly quoted package name
+
+Barewords caused unintuitive behavior when a subroutine with the same
+name as a package happened to be defined.  Thus, C<new Foo @args>,
+use the result of the call to C<Foo()> instead of C<Foo> being treated
+as a literal.  The recommended way to write barewords in the indirect
+object slot is C<new Foo:: @args>.  Note that the method C<new()> is
+called with a first argument of C<Foo>, not C<Foo::> when you do that.
+
+=head2 C<exists $Foo::{Bar::}> tests existence of a package
+
+It was impossible to test for the existence of a package without
+actually creating it before.  Now C<exists $Foo::{Bar::}> can be
+used to test if the C<Foo::Bar> namespace has been created.
+
+=head2 Better locale support
+
+See L<perllocale>.
+
+=head2 Experimental support for 64-bit platforms
+
+Perl5 has always had 64-bit support on systems with 64-bit longs.
+Starting with 5.005, the beginnings of experimental support for systems
+with 32-bit long and 64-bit 'long long' integers has been added.
+If you add -DUSE_LONG_LONG to your ccflags in config.sh (or manually
+define it in perl.h) then perl will be built with 'long long' support.
+There will be many compiler warnings, and the resultant perl may not
+work on all systems.  There are many other issues related to
+third-party extensions and libraries.  This option exists to allow
+people to work on those issues.
+
+=head2 prototype() returns useful results on builtins
+
+See L<perlfunc/prototype>.
+
+=head2 Extended support for exception handling
+
+C<die()> now accepts a reference value, and C<$@> gets set to that
+value in exception traps.  This makes it possible to propagate
+exception objects.  This is an undocumented B<experimental> feature.
+
+=head2 Re-blessing in DESTROY() supported for chaining DESTROY() methods
+
+See L<perlobj/Destructors>.
+
+=head2 All C<printf> format conversions are handled internally
+
+See L<perlfunc/printf>.
+
+=head2 New C<INIT> keyword
+
+C<INIT> subs are like C<BEGIN> and C<END>, but they get run just before
+the perl runtime begins execution.  e.g., the Perl Compiler makes use of
+C<INIT> blocks to initialize and resolve pointers to XSUBs.
+
+=head2 New C<lock> keyword
+
+The C<lock> keyword is the fundamental synchronization primitive
+in threaded perl.  When threads are not enabled, it is currently a noop.
+
+To minimize impact on source compatibility this keyword is "weak", i.e., any
+user-defined subroutine of the same name overrides it, unless a C<use Thread>
+has been seen.
+
+=head2 New C<qr//> operator
+
+The C<qr//> operator, which is syntactically similar to the other quote-like
+operators, is used to create precompiled regular expressions.  This compiled
+form can now be explicitly passed around in variables, and interpolated in
+other regular expressions.  See L<perlop>.
+
+=head2 C<our> is now a reserved word
+
+Calling a subroutine with the name C<our> will now provoke a warning when
+using the C<-w> switch.
+
+=head2 Tied arrays are now fully supported
+
+See L<Tie::Array>.
+
+=head2 Tied handles support is better
+
+Several missing hooks have been added.  There is also a new base class for
+TIEARRAY implementations.  See L<Tie::Array>.
+
+=head2 4th argument to substr
+
+substr() can now both return and replace in one operation.  The optional
+4th argument is the replacement string.  See L<perlfunc/substr>.
+
+=head2 Negative LENGTH argument to splice
+
+splice() with a negative LENGTH argument now work similar to what the
+LENGTH did for substr().  Previously a negative LENGTH was treated as
+0.  See L<perlfunc/splice>.
+
+=head2 Magic lvalues are now more magical
+
+When you say something like C<substr($x, 5) = "hi">, the scalar returned
+by substr() is special, in that any modifications to it affect $x.
+(This is called a 'magic lvalue' because an 'lvalue' is something on
+the left side of an assignment.)  Normally, this is exactly what you
+would expect to happen, but Perl uses the same magic if you use substr(),
+pos(), or vec() in a context where they might be modified, like taking
+a reference with C<\> or as an argument to a sub that modifies C<@_>.
+In previous versions, this 'magic' only went one way, but now changes
+to the scalar the magic refers to ($x in the above example) affect the
+magic lvalue too. For instance, this code now acts differently:
+
+    $x = "hello";
+    sub printit {
+	$x = "g'bye";
+	print $_[0], "\n";
+    }
+    printit(substr($x, 0, 5));
+
+In previous versions, this would print "hello", but it now prints "g'bye".
+
+=head2 E<lt>E<gt> now reads in records
+
+If C<$/> is a referenence to an integer, or a scalar that holds an integer,
+E<lt>E<gt> will read in records instead of lines. For more info, see
+L<perlvar/$/>.
+
+=head1 Supported Platforms
+
+Configure has many incremental improvements.  Site-wide policy for building
+perl can now be made persistent, via Policy.sh.  Configure also records
+the command-line arguments used in F<config.sh>.
+
+=head2 New Platforms
+
+BeOS is now supported.  See L<README.beos>.
+
+DOS is now supported under the DJGPP tools.  See L<README.dos>.
+
+MPE/iX is now supported.  See L<README.mpeix>.
+
+MVS (OS390) is now supported.  See L<README.os390>.
+
+=head2 Changes in existing support
+
+Win32 support has been vastly enhanced.  Support for Perl Object, a C++
+encapsulation of Perl.  GCC and EGCS are now supported on Win32.
+See F<README.win32>, aka L<perlwin32>.
+
+VMS configuration system has been rewritten.  See L<README.vms>.
+
+The hints files for most Unix platforms have seen incremental improvements.
+
+=head1 Modules and Pragmata
+
+=head2 New Modules
+
+=over
+
+=item B
+
+Perl compiler and tools.  See L<B>.
+
+=item Data::Dumper
+
+A module to pretty print Perl data.  See L<Data::Dumper>.
+
+=item Errno
+
+A module to look up errors more conveniently.  See L<Errno>.
+
+=item File::Spec
+
+A portable API for file operations.
+
+=item ExtUtils::Installed
+
+Query and manage installed modules.
+
+=item ExtUtils::Packlist
+
+Manipulate .packlist files.
+
+=item Fatal
+
+Make functions/builtins succeed or die.
+
+=item IPC::SysV
+
+Constants and other support infrastructure for System V IPC operations
+in perl.
+
+=item Test
+
+A framework for writing testsuites.
+
+=item Tie::Array
+
+Base class for tied arrays.
+
+=item Tie::Handle
+
+Base class for tied handles.
+
+=item Thread
+
+Perl thread creation, manipulation, and support.
+
+=item attrs
+
+Set subroutine attributes.
+
+=item fields
+
+Compile-time class fields.
+
+=item re
+
+Various pragmata to control behavior of regular expressions.
+
+=back
+
+=head2 Changes in existing modules
+
+=over
+
+=item CGI
+
+CGI has been updated to version 2.42.
+
+=item POSIX
+
+POSIX now has its own platform-specific hints files.
+
+=item DB_File
+
+DB_File supports version 2.x of Berkeley DB.  See C<ext/DB_File/Changes>.
+
+=item MakeMaker
+
+MakeMaker now supports writing empty makefiles, provides a way to
+specify that site umask() policy should be honored.  There is also
+better support for manipulation of .packlist files, and getting
+information about installed modules.
+
+Extensions that have both architecture-dependent and
+architecture-independent files are now always installed completely in
+the architecture-dependent locations.  Previously, the shareable parts
+were shared both across architectures and across perl versions and were
+therefore liable to be overwritten with newer versions that might have
+subtle incompatibilities.
+
+=item CPAN
+
+See <perlmodinstall> and L<CPAN>.
+
+=item Cwd
+
+Cwd::cwd is faster on most platforms.
+
+=item Benchmark
+
+Keeps better time.
+
+=back
+
+=head1 Utility Changes
+
+C<h2ph> and related utilities have been vastly overhauled.
+
+C<perlcc>, a new experimental front end for the compiler is available.
+
+The crude GNU C<configure> emulator is now called C<configure.gnu> to
+avoid trampling on C<Configure> under case-insensitive filesystems.
+
+C<perldoc> used to be rather slow.  The slower features are now optional.
+In particular, case-insensitive searches need the C<-i> switch, and
+recursive searches need C<-r>.  You can set these switches in the
+C<PERLDOC> environment variable to get the old behavior.
+
+=head1 Documentation Changes
+
+Config.pm now has a glossary of variables.
+
+F<Porting/patching.pod> has detailed instructions on how to create and
+submit patches for perl.
+
+L<perlport> specifies guidelines on how to write portably. 
+
+L<perlmodinstall> describes how to fetch and install modules from C<CPAN>
+sites.
+
+Some more Perl traps are documented now.  See L<perltrap>.
+
+=head1 New Diagnostics
+
+=over
+
+=item Ambiguous call resolved as CORE::%s(), qualify as such or use &
+
+(W) A subroutine you have declared has the same name as a Perl keyword,
+and you have used the name without qualification for calling one or the
+other.  Perl decided to call the builtin because the subroutine is
+not imported.
+
+To force interpretation as a subroutine call, either put an ampersand
+before the subroutine name, or qualify the name with its package.
+Alternatively, you can import the subroutine (or pretend that it's
+imported with the C<use subs> pragma).
+
+To silently interpret it as the Perl operator, use the C<CORE::> prefix
+on the operator (e.g. C<CORE::log($x)>) or by declaring the subroutine
+to be an object method (see L<attrs>).
+
+=item Bad index while coercing array into hash
+
+(F) The index looked up in the hash found as the 0'th element of a
+pseudo-hash is not legal.  Index values must be at 1 or greater.
+See L<perlref>.
+
+=item Bareword "%s" refers to nonexistent package
+
+(W) You used a qualified bareword of the form C<Foo::>, but
+the compiler saw no other uses of that namespace before that point.
+Perhaps you need to predeclare a package?
+
+=item Can't call method "%s" on an undefined value
+
+(F) You used the syntax of a method call, but the slot filled by the
+object reference or package name contains an undefined value.
+Something like this will reproduce the error:
+
+    $BADREF = 42;
+    process $BADREF 1,2,3;
+    $BADREF->process(1,2,3);
+
+=item Can't coerce array into hash
+
+(F) You used an array where a hash was expected, but the array has no
+information on how to map from keys to array indices.  You can do that
+only with arrays that have a hash reference at index 0.
+
+=item Can't goto subroutine from an eval-string
+
+(F) The "goto subroutine" call can't be used to jump out of an eval "string".
+(You can use it to jump out of an eval {BLOCK}, but you probably don't want to.)
+
+=item Can't localize pseudo-hash element
+
+(F) You said something like C<local $ar-E<gt>{'key'}>, where $ar is
+a reference to a pseudo-hash.  That hasn't been implemented yet, but
+you can get a similar effect by localizing the corresponding array
+element directly -- C<local $ar-E<gt>[$ar-E<gt>[0]{'key'}]>.
+
+=item Can't use %%! because Errno.pm is not available
+
+(F) The first time the %! hash is used, perl automatically loads the
+Errno.pm module. The Errno module is expected to tie the %! hash to
+provide symbolic names for C<$!> errno values.
+
+=item Cannot find an opnumber for "%s"
+
+(F) A string of a form C<CORE::word> was given to prototype(), but
+there is no builtin with the name C<word>.
+
+=item Character class syntax [. .] is reserved for future extensions
+
+(W) Within regular expression character classes ([]) the syntax beginning
+with "[." and ending with ".]" is reserved for future extensions.
+If you need to represent those character sequences inside a regular
+expression character class, just quote the square brackets with the
+backslash: "\[." and ".\]".
+
+=item Character class syntax [: :] is reserved for future extensions
+
+(W) Within regular expression character classes ([]) the syntax beginning
+with "[:" and ending with ":]" is reserved for future extensions.
+If you need to represent those character sequences inside a regular
+expression character class, just quote the square brackets with the
+backslash: "\[:" and ":\]".
+
+=item Character class syntax [= =] is reserved for future extensions
+
+(W) Within regular expression character classes ([]) the syntax
+beginning with "[=" and ending with "=]" is reserved for future extensions.
+If you need to represent those character sequences inside a regular
+expression character class, just quote the square brackets with the
+backslash: "\[=" and "=\]".
+
+=item %s: Eval-group in insecure regular expression
+
+(F) Perl detected tainted data when trying to compile a regular expression
+that contains the C<(?{ ... })> zero-width assertion, which is unsafe.
+See L<perlre/(?{ code })>, and L<perlsec>.
+
+=item %s: Eval-group not allowed, use re 'eval'
+
+(F) A regular expression contained the C<(?{ ... })> zero-width assertion,
+but that construct is only allowed when the C<use re 'eval'> pragma is
+in effect.  See L<perlre/(?{ code })>.
+
+=item %s: Eval-group not allowed at run time
+
+(F) Perl tried to compile a regular expression containing the C<(?{ ... })>
+zero-width assertion at run time, as it would when the pattern contains
+interpolated values.  Since that is a security risk, it is not allowed.
+If you insist, you may still do this by explicitly building the pattern
+from an interpolated string at run time and using that in an eval().
+See L<perlre/(?{ code })>.
+
+=item Explicit blessing to '' (assuming package main)
+
+(W) You are blessing a reference to a zero length string.  This has
+the effect of blessing the reference into the package main.  This is
+usually not what you want.  Consider providing a default target
+package, e.g. bless($ref, $p || 'MyPackage');
+
+=item Illegal hex digit ignored
+
+(W) You may have tried to use a character other than 0 - 9 or A - F in a
+hexadecimal number.  Interpretation of the hexadecimal number stopped
+before the illegal character.
+
+=item No such array field
+
+(F) You tried to access an array as a hash, but the field name used is
+not defined.  The hash at index 0 should map all valid field names to
+array indices for that to work.
+
+=item No such field "%s" in variable %s of type %s
+
+(F) You tried to access a field of a typed variable where the type
+does not know about the field name.  The field names are looked up in
+the %FIELDS hash in the type package at compile time.  The %FIELDS hash
+is usually set up with the 'fields' pragma.
+
+=item Out of memory during ridiculously large request
+
+(F) You can't allocate more than 2^31+"small amount" bytes.  This error
+is most likely to be caused by a typo in the Perl program. e.g., C<$arr[time]>
+instead of C<$arr[$time]>.
+
+=item Range iterator outside integer range
+
+(F) One (or both) of the numeric arguments to the range operator ".."
+are outside the range which can be represented by integers internally.
+One possible workaround is to force Perl to use magical string
+increment by prepending "0" to your numbers.
+
+=item Recursive inheritance detected while looking for method '%s' in package '%s'
+
+(F) More than 100 levels of inheritance were encountered while invoking a
+method.  Probably indicates an unintended loop in your inheritance hierarchy.
+
+=item Reference found where even-sized list expected
+
+(W) You gave a single reference where Perl was expecting a list with
+an even number of elements (for assignment to a hash). This
+usually means that you used the anon hash constructor when you meant 
+to use parens. In any case, a hash requires key/value B<pairs>.
+
+    %hash = { one => 1, two => 2, };   # WRONG
+    %hash = [ qw/ an anon array / ];   # WRONG
+    %hash = ( one => 1, two => 2, );   # right
+    %hash = qw( one 1 two 2 );                 # also fine
+
+=item Undefined value assigned to typeglob
+
+(W) An undefined value was assigned to a typeglob, a la C<*foo = undef>.
+This does nothing.  It's possible that you really mean C<undef *foo>.
+
+=item Use of reserved word "%s" is deprecated
+
+(D) The indicated bareword is a reserved word.  Future versions of perl
+may use it as a keyword, so you're better off either explicitly quoting
+the word in a manner appropriate for its context of use, or using a
+different name altogether.  The warning can be suppressed for subroutine
+names by either adding a C<&> prefix, or using a package qualifier,
+e.g. C<&our()>, or C<Foo::our()>.
+
+=item perl: warning: Setting locale failed.
+
+(S) The whole warning message will look something like:
+
+       perl: warning: Setting locale failed.
+       perl: warning: Please check that your locale settings:
+               LC_ALL = "En_US",
+               LANG = (unset)
+           are supported and installed on your system.
+       perl: warning: Falling back to the standard locale ("C").
+
+Exactly what were the failed locale settings varies.  In the above the
+settings were that the LC_ALL was "En_US" and the LANG had no value.
+This error means that Perl detected that you and/or your system
+administrator have set up the so-called variable system but Perl could
+not use those settings.  This was not dead serious, fortunately: there
+is a "default locale" called "C" that Perl can and will use, the
+script will be run.  Before you really fix the problem, however, you
+will get the same error message each time you run Perl.  How to really
+fix the problem can be found in L<perllocale> section B<LOCALE PROBLEMS>.
+
+=back
+
+
+=head1 Obsolete Diagnostics
+
+=over
+
+=item Can't mktemp()
+
+(F) The mktemp() routine failed for some reason while trying to process
+a B<-e> switch.  Maybe your /tmp partition is full, or clobbered.
+
+=item Can't write to temp file for B<-e>: %s
+
+(F) The write routine failed for some reason while trying to process
+a B<-e> switch.  Maybe your /tmp partition is full, or clobbered.
+
+=item Cannot open temporary file
+
+(F) The create routine failed for some reason while trying to process
+a B<-e> switch.  Maybe your /tmp partition is full, or clobbered.
+
+=back
+
+=head1 BUGS
+
+If you find what you think is a bug, you might check the headers of
+recently posted articles in the comp.lang.perl.misc newsgroup.
+There may also be information at http://www.perl.com/perl/, the Perl
+Home Page.
+
+If you believe you have an unreported bug, please run the B<perlbug>
+program included with your release.  Make sure you trim your bug down
+to a tiny but sufficient test case.  Your bug report, along with the
+output of C<perl -V>, will be sent off to <F<perlbug@perl.com>> to be
+analysed by the Perl porting team.
+
+=head1 SEE ALSO
+
+The F<Changes> file for exhaustive details on what changed.
+
+The F<INSTALL> file for how to build Perl.
+
+The F<README> file for general stuff.
+
+The F<Artistic> and F<Copying> files for copyright information.
+
+=head1 HISTORY
+
+Written by Gurusamy Sarathy <F<gsar@umich.edu>>, with many contributions
+from The Perl Porters.
+
+Send omissions or corrections to <F<perlbug@perl.com>>.
+
+=cut