|Come for the quick hacks, stay for the epiphanies.
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.