I accidentally clicked on April 2012 just now, and I went into the following thread. It has an alphabetized list of all those acronyms and what they mean. I remember someone posting here asking what they meant, and now there's a list! A lot of them there I have never seen used before, and some aren't on there (like OOT=out of town), but it's better than nothing! Just thought I'd share.
http://forums.theknot.com/Sites/theknot/Pages/Main.aspx/wedding-club-boards_april-2012-weddings_congrats-welcome-please-read-first