For a guy that's never been much of a regular expression wizard, this is still a good document. I've spent many hours trying to decipher strings of Perl compatible printer noise so I've learned to use them sparingly. It's my "pay it forward" for the next guy that sits in this not-so-comfy office chair.
Surly someone would have come up with a more natural-language way of processing strings by now? Instead of '^\d' one could write 'match if str starts with digit.'