+__END__
+PERL_REVISION (Oldsyms.U):
+ In a Perl version number such as 5.6.2, this is the 5.
+ This value is manually set in patchlevel.h
+
+PERL_VERSION (Oldsyms.U):
+ In a Perl version number such as 5.6.2, this is the 6.
+ This value is manually set in patchlevel.h
+
+PERL_SUBVERSION (Oldsyms.U):
+ In a Perl version number such as 5.6.2, this is the 2.
+ Values greater than 50 represent potentially unstable
+ development subversions.
+ This value is manually set in patchlevel.h
+
+PERL_APIVERSION (Oldsyms.U):
+ This value is manually set in patchlevel.h and is used
+ to set the Configure apiversion variable.
+
+CONFIGDOTSH (Oldsyms.U):
+ This is set to 'true' in config.sh so that a shell script
+ sourcing config.sh can tell if it has been sourced already.
+
+PERL_CONFIG_SH (Oldsyms.U):
+ This is set to 'true' in config.sh so that a shell script
+ sourcing config.sh can tell if it has been sourced already.
+
+PERL_API_REVISION (patchlevel.h):
+ This number describes the earliest compatible PERL_REVISION of
+ Perl ("compatibility" here being defined as sufficient binary/API
+ compatibility to run XS code built with the older version).
+ Normally this does not change across maintenance releases.
+ Please read the comment in patchlevel.h.
+
+PERL_API_VERSION (patchlevel.h):
+ This number describes the earliest compatible PERL_VERSION of
+ Perl ("compatibility" here being defined as sufficient binary/API
+ compatibility to run XS code built with the older version).
+ Normally this does not change across maintenance releases.
+ Please read the comment in patchlevel.h.
+
+PERL_API_SUBVERSION (patchlevel.h):
+ This number describes the earliest compatible PERL_SUBVERSION of
+ Perl ("compatibility" here being defined as sufficient binary/API
+ compatibility to run XS code built with the older version).
+ Normally this does not change across maintenance releases.
+ Please read the comment in patchlevel.h.
+
+PERL_PATCHLEVEL (Oldsyms.U):
+ This symbol reflects the patchlevel, if available. Will usually
+ come from the .patch file, which is available when the perl
+ source tree was fetched with rsync.
+
+config_args (Options.U):
+ This variable contains a single string giving the command-line
+ arguments passed to Configure. Spaces within arguments,
+ quotes, and escaped characters are not correctly preserved.
+ To reconstruct the command line, you must assemble the individual
+ command line pieces, given in config_arg[0-9]*.
+
+config_arg0 (Options.U):
+ This variable contains the string used to invoke the Configure
+ command, as reported by the shell in the $0 variable.
+
+config_argc (Options.U):
+ This variable contains the number of command-line arguments
+ passed to Configure, as reported by the shell in the $# variable.
+ The individual arguments are stored as variables config_arg1,
+ config_arg2, etc.
+