Mr. Rewrite decided to try another video blog after seeing a store offering DVD's and CD's. He knows not to use apostrophe-S to create plurals with ordinary words -- e.g. banana's -- but what's the deal with abbreviations and acronyms?
He'll turn to The Chicago Manual of Style for the rule, but this one's consistent in all of his usage guides, including the AP Stylebook: With very few exceptions, use S, not apostrophe-S, to create plurals of acronyms, abbreviations and any other words made from capital letters.
This rule covers you on SUVs, URLs and even plurals of capital letters (e.g. the three Rs). It also covers numbers used as plural nouns, such as the 1990s.
Here are the main exceptions: (1) Use apostrophe-S for clarity when making plurals of abbreviations with two or more periods (e.g. Ph.D.'s, M.A.'s); (2) Go with apostrophe-S when making plurals of lowercase letters (e.g. x's, y's).
Mainstream U.S. media outlets usually are bound by AP style, so there's no reason for Mr. Rewrite to find hundreds of references on Google News to 1990's, SUV's, DVD's and CD's. Some, but not many, of these are correct uses of the possessive (e.g. "She survived her SUV's roll down a hill).