Re^3: What would you put on a Perl mug?

[Perl Mouse]

I didn't think about pack/unpack but that's because it's something I so rarely use.

That's exactly why I'd put it on a mug. Regular expressions is what people use all the time, and so they'll know most, if not all, of the syntax already. And since Perl regular expressions are firmly based on Henry Spencer's library, a lot of non-Perl users will not have problems with Perl regular expressions.

OTOH, I don't use pack and unpack that often. That's why I need to look up its syntax when I do use it.