Jose wrote:
The pluralization of a single letter is the only context in which an
apostrophe is appropriate to form the plural.

For instance: CDs, ATVs, Oakland A's. ABCs, A's, B's and C's.

Source: AP Stylebook and Libel Manual, OSU Department of Journalism.

And the New York Times stylebook says that acronym plurals should be
spelled with an apostrophe: one DVD, three DVD's.

That doesn't make it right.


Language is nothing but a set of agreed upon rules. The way the rules get
changed is by those that carry a lot of weight has far as language is
concerned change them. The AP and NYT fit this description.

There is no law that says you cant spell dog, C A T. Though there will be a
lot of people who don't know what you are taking about.