In your rush to show how much you know about Regexes, you forgot what the original question was.
And the question was "do I have to suffer for the effects of naughty regexes if somebody else in the same environment is using them?"
The question WAS NOT "show me how smart you are with @+ and @-"
Ask around. Everybody in the Monastery believes that Ovid knows a few things about regexes and he wasn't waiting for your self-promoting remarks to come out of the darkness.