A friend wrote me yesterday with this punctuational query (edited here to cloak some details):
I am teaching an online course … this semester … The course material is mostly pre-written for me, but I’ve been going through it myself, of course. One thing I noted is that acronyms [what I would call initialisms; see below] are sometimes made plural with the letter s, sometimes with apostrophe s. I guess what bothers me most is the inconsistency.
I was looking through Language Log and your blog for the topic of plural acronyms with and without apostrophes, but came up blank. Do you know of anything on current thoughts on this topic, or have any yourself?
MBA (Master in Business Administration) is an initialistic name of a degree; is its plural MBAs (no apostrophe) or MBA’s?