It's really about punctuation, but "Gutenberg and Punctuation" loses the alliterative effect, so I opted for taking alliterary license this time.
This year my boss gave a Page-A-Day calendar to each of us in our group. The lady next door got a Brevity calendar like the one I had last year, and I got Eats, Shoots & Leaves, which is all about the joys of proper punctuation.
Today, Lynne Truss quotes from the Oxford Companion to English Literature: "There never was a golden age in which the rules for the possesive apostrophe were clear-cut and known, understood and followed by most educated people." I must not be "most educated people."
I already knew, from my days trying to become a romance writer, that printers were responsible for the rule about the period ALWAYS belonging inside the ending quotation marks. The typesetting machines had a doohickey with a period-quote on it but a quote-period doohickey did not exist. Hence, the period always goes inside the quote. Same for the comma.
The last several days of my calendar trace the evolution of the use of the apostrophe, and all of the changes were the result of decisions made by printers.
First, in Shakespearean times, printers started using the apostrophe to substitute for missing letters. That's all the tiny apostrophe did. Possessives were on their own without any special punctuation.
In the 17th Century, printers started using apostrophes for singular possessives. In the 18th Century, printers added them for plural possessives as well.
If you've got your eyes open at all, you can see the trend. It's because of Gutenberg the Genius and his Marvelous Invention that we have apostrophes in use today, if only most of us could remember the right way to use them:
1. When letters are missing (gov't).
2. When it's a non-pronoun plural (the girl's dress, but NOT the dress is hers / the girls' dresses, but NOT the dresses are theirs).
And maybe there's a morphing of the language again, because people often choose to use it for plurals of acronyms or numbers (RUS's or 100's) because sometimes it looks funny without the apostrophe. But these haven't become hard-and-fast rules yet. Personally, I'm for using the apostrophe with plural acronyms but not with plural numbers.
Given a little more time, though, I'm guessing the printers will let us know what's correct for sure.