Avon's new makeup line aimed at youngsters prompted an interesting thread at Testy Copy Editors. Avon styles the product line as mark. (lowercase and with the period). What should editors do? Here's my take:

Proper nouns are capitalized. That goes for Mark and E.E. Cummings and Matchbox Twenty.
And punctuation is a device meant to clarify the language, not muck it up. So that means Mark and Yahoo and Guess.

Avon can do whatever it wants with its logo. But we make the rules on capitalization and punctuation.

So who has it right?
Forbes
ABC News (last item)
Edmonton Journal
Arkansas Democrat-Gazette
Huntington (W.V.) Herald Dispatch
Cosmo

And who has it wrong?
Denver Post
Associated Press, rerun a lot
Southwest Florida News-Press
Winchester (Va.) Star
Florida Today