And this is why I think you've got blinders on.  The cites aren't for headline usage only. Perhaps you missed the cite for The Observer (England) July 22, 2007, which uses HP for Harry Potter in the article text (not in the headline) and doesn't ever spell out "Harry Potter"; it uses HP only.  Or the Atlanta Journal-Constitution, July 7, 2007, which spells it out "HP (Harry Potter)" in the text, not in the headline. Here's a new one, going the other way: " Personally, I reckon you're either a Fellowship Of The Rings (FotR) fan or a Harry Potter (HP) girl. In this instance a bit of owning up has to be done: I've read all the HP books...." The Sunday Telegraph, January 6, 2002.  That's also in the text, not in the headline.  If that will help, I'll add it to the other discussion as well; I stopped digging them up since it was unclear what the problem with the existing cites was.