I read your comment and decided to do read up on some theory behind it. I came across this: http://cstheory.stackexchange.com/q/448/4052 http://cstheory.stacke

I read your comment and decided to do read up on some theory behind it. I came across this: http://cstheory.stackexchange.com/q/448/4052 http://cstheory.stackexchange.com/q/448/4052 From the highest rated answer: Larry Wall proposed that we use "regular expression" for the formalism Kleene proposed, and "regex" for expressions for the widely used extensions. It's a fairly widely followed convention. If you want to make it clear that you are talking about regular expressions in the formal languages sense, it is usually not difficult to translate into talk of regular languages.