A Triumph for Punctuation Sticklers

My friend Sara is a librarian at a fancy prep school near Boston. Last week, the library unveiled its new online catalog, and it contained an apostrophe catastrophe! Check out the middle of this screen shot, under Formats:


Some of the librarians argued that it was correct to put an apostrophe before the "s" in an abbreviation to make it plural, but eventually the truth revealed itself in the form of an MLA handbook. The library planned to correct the error in its catalog. Hallelujah! Thanks, Sara!