Is there a particular regular expression engine that is used by mod_rewrite on Apache 1.3?
I want to know so I can get a list of supported and non-supported features.
For 1.3, it looks like POSIX:
(I guess we were supposed to assume that meant 1.2 and up.)
For current versions, again from the docs:
From there, they provide some basics but mostly point you at Perl's regex docs for full information.