What is a word mark?

Speaking of Google and trademarks, an interesting article on Google's own trademarks is Don't "Hitchhike"A Ride On Google's Trademarks and URLs by Russell Shaw. Only thing is that he defines a "word mark" as "similar to a trademark, but more of a logo than a business name," which it isn't. I don't blame him for being confused. The term is not found in the index of McCarthy's definitive treatment, nor in the INTA glossary on line. But one thing is for sure: A word mark is a trademark, it's not "like a trademark." And describing it as being like a logo is misleading -- many logos don't have any words in 'em at all. In fact, a word mark is nothing more or less than a trademark consisting of a word or words. (See, e.g., American Home Products Corp. v. Johnson Chemical Co., Inc.,589 F.2d 103, 200 U.S.P.Q. 417 (2nd Cir. 1978). If you must. )