This topic came up recently in my own task of proofreading. If you have an acronym or another all capital letter word, how do you make it plural or possessive? And then once you do, is the added pluralization or possession in all caps or not?
The short answer is that any pluralization or possession is added to the base word, but in this case, it is NOT in all caps:
- There are never any ATMs around when you need them.
- ADOT’s signs don’t always help the traffic flow.
There are times where you will need to use an apostrophe to avoid confusion:
- Her report card had all A’s and B’s.
Here, the “A’s and B’s” are not possessive, but it could be confusing to leave the apostrophe out in “As” as it is a different (and real) word. In this case, the apostrophe in “B’s” is for consistency.
There is some confusion when using abbreviations because making the abbreviations possessive may be different than making the entire original words possessive:
- The United States’ geography is so varied and interesting.
- The U.S.’s geography is so varied and interesting.
You will use the rules depending on how it sounds. The “United States” spelled out does not need an apostrophe and “s” because you don’t say the extra “s.” But using the abbreviation “U.S.,” you would say the extra “s,” so would add the apostrophe and “s.” See Apostrophail!.
Just remember that only the original acronym or abbreviation should be in caps and any pluralization or possession would be added to that, but not in caps.