in reply to Naughty Regular Expressions and mod_perl

Since mod_perl is a persistent Perl interpreter embedded in the Web server, it seems to me that any reference to these variables will impact all regex matches in a mod_perl environment, regardless of whether or not my code actually uses those variables. Is this the case?

Yes, that's what I've been told.

You could try checking with Devel::SawAmpersand if you wanted to prove it to yourself.