Although some of the terms are general internet acronyms rather than being OSR-specific (for example, I'm pretty sure I've seen "WTF" in another context before) I wanted to give that list a shout-out. Having been working on a list of my own here for a week or two prior, now I don't have to finish it! But more importantly, it's a good lexicon, it's a good start, and seeing new faces to the hobby, this is a good way to provide a glossary that, to date, is maintained via oral tradition rather than by reference.
Here compiled is an extension to the above pastebin - not knowing how to contact its maintainer to suggest addendums - along with some clarifications that I would personally supply.
- BitC) Blood in the Chocolate - A module for the LotFP system themed around Willy Wonka, but embedded with controversy surrounding the use of sexual themes to drive interest.
- BTAM) Better Than Any Man - A supplement for the LotFP system containing an adventure, but also supporting resources, such as new spells or magic items.
- BXE) Basic / eXpert Essentials - the original working title of OSE.
- DAC) Descending Armor Class - used in original TSR editions, descending AC means "lower AC is harder to hit."
- D&D) Dandies and Daffodils - the much anticipated sixth edition of WotC's D&D with significantly more emphasis on player introspection and the poetic aspect of collaborative storytelling in a role-playing context. Occasionally abbreviated DnD.
- FOE) Foul Odor Expressed - a reference to the typically poor hygiene associated with the less savory members of the hobby; commonly used in conjunction with GYG) Grogs, You Gag!.
- OSR) Old School Renaissance - the name of the movement bringing D&D back to it's roots!
- RTCS) Red Tide Campaign Setting - [RESEARCH]
- ToEE) Temple of Elemental Evil - A module for AD&D, published as a sequel for VoH, originally published in 1985 known for its lethality and as a source for anecdotal stories stemming from its inclusion in Gary Gygax's home game.
- SWN) Stars Without Number - a sci-fi system written by Kevin Crawford that draws on some influences from Traveler.
- VoH) Village of Hommlet - A self-described introductory AD&D module and the first in the Temple of Elemental Evil series.
- WoHF) Wilderlands of High Fantasy - A campaign setting published by Judges Guild originating in 1977, having originated in CSIO.
- ~ZOZ) not an acronym. I seem to recall this originated as an error in an AD&D PDF, where the word "fun" was mistranspiled as "~ZOZ" - in either case, I hate this term. No express reason.