I'm guessing you guys are talking about the TDP chart, which is in reference to the mil-spec requirements, not features. I think at the time it was made only Colt met all of the specs. Since then it has been updated a time or two... Anyway, here is a link to the author of said charts webpage.
Edit... The link looks like it isn't there anymore. Anyway the author is Rob_S and he has been around many forums for a long time. His actual website is tacticalyellowvisor.net