Riddle of the day:
Q: What do you make plural with an apostrophe?
That’s right, nothing. Not a regular word, like “book” or “company,” not a word that ends in S, like “stress” or “bus,” not a numerical date, like “1990” or “’89,” not a technical term, like “data” or “control,” not a proper noun, like “WinForm” or “dotcom,” and not an acronym, like “CD” or “PC.” I don’t care that you’ve seen things made plural with an apostrophe S all over the place. It’s wrong wrong wrong.
Apostrophes serve two purposes and two purposes only. They show where a word has been contracted (like don’t and ’91), and they show possession. In essence, possessives are contractions too, because without that fun little apostrophe S you’d have to write “of the <whatever>” all the time.
You know the easy plurals: “book” becomes “books” and Y becomes IE in when “company” becomes “companies.” Words that end in S usually just get an ES, like “stress” becoming “stresses,” but sometimes they get another S, like when “bus” becomes “busses.” Let’s take a little look at the harder ones, the mistakes we see in the newspaper (known for their scrupulous editors), on the television, and in advertising, and that drive folks like me bonkers.
When you make a numerical date plural, you just add an S. Really. “The 1990s were boom years.” See? Doesn’t that just look right, all clean and clear? You get to use an apostrophe on the front end if you abbreviate, although it has become acceptable to leave it off if the context is clear. So you can say “in the ‘90s” or “in the 90s” without a squawk from hard-nosed editors. But you don’t get to plop an apostrophe on the back to make it plural.
“Data” is a tough one. “Data” is already plural, so you have to treat it like any other plural noun (people or feet, for instance) as far as the verb goes in proper non-technical English. No S. “Control” just gets an S, like records or transfers. Other technical terms don’t get special treatment either. “RegEx” becomes “RegExes,” which is a little more complicated, but you can see the logic from plain old “stress” that became “stresses” because X gets treated like an S.
Proper nouns, like other nouns, just get an S. When you collect all the people in my family, you have the SPILLERS. If you collect them at my house, the invitation says to gather at the SPILLERS' See that nice possessive apostrophe AFTER the S? It works the same way for product names, even their short versions, so it’s “WinForms” and “dotcoms.”
Okay, here’s the one that seems to upset the kettle of fish all over the kitchen floor. Acronyms are made by taking the first letter of a series of words and combining them into a new, shorter word (unless you’re in the military, in which case any collection of front-end letters will suffice—that’s how we got ID from “identification,” for instance). So “Base Class Library” becomes “BCL” and “Base Class Libraries” becomes “BCLs.” “Personal Computer” becomes “PC” becomes “PCs,” and “Compact Disk” becomes “CD” becomes CDs.” See? That’s not so complicated.