The "Blog" of "Unnecessary" Quotation Marks

Have you noticed that people, especially when they're writing signs, tend to use quotation marks for sometimes the most bizarre reasons? For example, above the entrance to the garage behind the stadium here on campus--perhaps you've noticed if you park there--it clearly reads:

"CLEARANCE"
"7 FOOT 8 INCHES"

Quotation marks and all. I'm not sure what this means.

The "correct" use of quotation marks is to indicate quoted speech. Often (and I think this is just as correct, though some English mavens will disagree) we also use them to indicate that a word doesn't mean what it seems to mean. Roughly this means the same as saying "so-called," as in referring to tabloids as "newspapers."

In popular sign usage, though, quotation marks are sometimes used for emphasis. I guess this might make sense, since often signs are already written in capital letters, so it's difficult to make any particular words stand out. But that creates a problem: how are we to know whether quotation marks are meant to emphasize a word, or to indicate that it doesn't mean what it says? There was a pawn shop I used to drive by in Columbia, that proudly advertised that it would buy anything "except guns." I always took that to mean that you could in fact sell your guns there, but maybe you had to go around the back and wear a ski mask if you wanted to do it.

It seems I'm not alone in noticing this. There is an entire bog devoted to reporting cases of it, actually: The "Blog" of "Unnecessary" Quotation Marks. Check it out for some "good" examples.