$^ The name of the current top-of-page format for the currently selected output channel. The default is the name of the filehandle with

$[ This variable stores the index of the first element in an array, and of the first character in a substring. The default is 0, but you could

@- $-[0] is the offset of the start of the last successful match

$^O The name of the operating system under which this copy of Perl was built, as determined during the configuration process. For examples

$^H WARNING: This variable is strictly for internal use only. Its availability, behavior, and contents are subject to change without notice

$^C The current value of the flag associated with the -c switch. Mainly of use with -MO=... to allow code to alter its behavior

$OUTPUT_FIELD_SEPARATOR

$INPLACE_EDIT

%ERRNO

$WARNING