Hi midnight
As someone with some 'proofchecking' responsibilities in my company, I refuse to allow apostrophes for the plurals of acronyms. I suppose it is a personal thing, but I just can't abide it.
Similarly, I refuse to countenance the abbreviations of decades as 60's and always change it to '60s, and so on.
These are, however, my idiosyncrasies. I think that the apostrophed form will eventually prevail, merely because I see more and more people using it these days as a matter of course. I may wish to preserve the distinction between the various uses: "the PC's peripherals are useless" (singular, possessive); "the PCs have useless peripherals" (plural); and "the PCs' hard drives are useless" (plural, possessive), if only to avoid the plural possessive "the PC's' peripherals are useless and may need to be recalled". (I know this is stretching it, but amateur language mavens like me need our hard cases in order to justify bad, or simply prejudiced, laws!)
cheer
the sunshine warrior
