I don't think a search searches for any text in a sig, just the text in the post's themselves. At Least not with the search I just tried.
For quite awhile (the first 4+ years this site has been operational), we weren't able to 'Tag' post's with specific tag words. but now we can. Not sure how many here are aware of that.
So many times people say "Use the search function. That's what it's there for"
Well, once you start getting more and more post's, throughout the entire site, and those posts start getting a little off topic, you're bound to get many results in a search that seem completely irrelevant to what one is looking for.
I usually use the Google search feature, which let's you search just the site you're viewing. Seems to work pretty good, IMO.
AKA: Tim & 'The Adventure Cycle' VROC #24567, NEVROC, SteelCity VROC
"When life throws you curves,
Aim for the apex."