Interesting LCD diminsions

I've been noticing that advertised sizes of LCD's don't exactly match those of the specified diminsions. For example, on Newegg, most of their advertised 19" LCD's have demisions of 17x17x8. (give or take a few 10ths of an inch). One even has a 15x15x6 specification. Now correct me if I'm wrong here, but no matter how you measure that, it does not even come close to 19".

However, some advertised LCD's have specifications that exceed the 19" advertised size so I would have to believe that these companies are in fact selling 19" monitors.

If I'm not mistaken, wasn't manufacurers made to list the actual "viewable" size on CRT monitors? Does this not apply to LCD's?