$NR

$<digits> ($1, $2, ...) Contains the subpattern from the corresponding set of capturing parentheses from the last successful pattern

HANDLE->format_top_name(EXPR)

${^RE_TRIE_MAXBUF} Controls how certain regex optimisations are applied and how much memory they utilize. This value by default is 65536 which

${^GLOBAL_PHASE} The current phase of the perl interpreter. Possible values are:

$^R The result of evaluation of the last successful (?{ code }) regular expression assertion (see

$PERLDB

@LAST_MATCH_START

$: The current set of characters after which a string may be broken to fill continuation fields (starting with ^)

$SUBSCRIPT_SEPARATOR