Acronym Guide is made for [new] players that have a hard time getting used to the various acronyms used in WoW. What it does is replace the common abriviations with a hyperlink, that on mouse over or click, displays a tool tip with an short explanation of what it means.
But in Westfall itself, when people say DM they mean Deadmines, since no level 16 player is trying to run Dire Maul. So sometimes you need to be careful, because new players will abbreviate what they know, and not everyone will have this addon and be educated about Dire Maul versus Deadmines or Mana Tombs versus Magister's.
In my experience, 99.9% of the time DM = Deadmines, not Dire Maul, though this might be because I play alliance character and the trade is full of "lf boost DM" beggers.
I'm checking the definitions.lua right now and some things that came to my mind:
*WTC - Want to Craft (like LFW)
*Strat could now more often also mean CoS
*ZF = Zul'Farrak (42-50 level instance in Tanaris)
*CoT = Caverns of Time (contains four instances in Tanaris)
*RFK = Razorfen Kraul (23-31 level instance in The Barrens)
*RFD = Razorfen Downs (33-41 level instance in The Barrens)
*In my realm (EU), heroics are pretty much always shortened as 'hc': "lfg hc vh".
*ot = offtank
*in AB: GM = Gold Mine, LM = Lumber Mill, ST = Stables (in addition to BS)
*SWP = Sunwell Plateau (a level 70 25-man raid instance in Isle of Quel'Danas) or Shadow Word: Pain (a priest spell)
*ZA = Zul'Aman (a level 70 10-man raid instance in Ghostlands)
*SoS = Swamp of Sorrows (a level 35-45 zone in the Eastern Kingdoms)
*TK = Tempest Keep (a complex of three normal and one raid instance in Netherstorm, sometimes meant as the raid instance "Tempest Keep - The Eye")
*SP = The Slave Pens (62-64 level instance in Coilfang Reservoir, Zangarmarsh)
*UB = The Underbog (63-65 level instance in Coilfang Reservoir, Zangarmarsh)
*SV = The Steamvault (70 level instance in Coilfang Reservoir, Zangarmarsh) (or I guess someone could be talking about Saved Variables too :P)
*When Cloak of Shadows was new it was talked about as CoS, though nowadays I guess it might more often be CloS.
Class abilities and talents have so many abbreviations, spelled so many ways, that they may be beyond the ability of an addon to usefully assist.
With class spells im gonna go with path of least resistance. If there is an over lap somewhere, then i'll add it but im not going to go out of the way to keep up with the various ways to abriviate "Cloak of Shadows". IE the entry for "MC", it's listed as Molten Core and Mind Control, as they overlap.
The zone name "Dragonblight", not "Dragon Blight". ;)
Also, I think saying "Level 80 raid instance in Dragonblight" would be more informative; all level 80 raids have a 10-man and 25-man version, so giving the level implies the size, whereas just giving the size doesn't necessarily imply the level... you could reasonably describe Blackwing Lair or Sunwell Plateau as "10-25 man raid instance"s at level 80.