If you’re like me, you do look to The New York Times for punctuation guidance, even if it does seem like “newspaper style” has taken on a life of its own (which frankly I’m sorry to see).
I just read a story and here’s how The New York Times puts together a plural acronym:
C.E.O.s
Yes! Caps, of course, but what about those periods! And then the trailing lowercase “s.”
Interesting. Okay, what are our options? What are our choices?
CEOs…LOOKS GOOD!
CEO’s…WRONG. One letter plus apostrophe plus “s” is the plural  for a single letter or single number (X’s, I’s and T’s), but CEOs is three letters, which gives credence to the “CEOs” form.
But what about the periods? Well, let’s ask ourselves: What does the acronym stand for? This acronym is “Chief Executive Officer,” which is a mouthful, but since I know a) we use the expression “CEO” all the time and b) it is commonly accepted: I could say “CEO” and be understood by a substantial part of the population. So why the periods? I’m for streamlining the whole kit and kaboodle, so my personal preference would be CEOs.
You know what? I’ll ask my buddy at the NYTimes and get an opinion: what triggers the use of periods with a multi-level acronym, or are periods between letter combinations of two letters and up—C.E.O.s—the style right now?
So, NYTimes’ style says acronyms use periods between the capital letters and no apostrophe accompanies the lowercase “s” in the plural: C.E.O.s. Hmm. Still not enthused about the periods.
Will report back.