OC = Open Carry
CC = Concealed Carry
CCW = the crime of carrying concealed without a permit, but most people use it to denote a permit, or CCing legally, or the firearm they use for CC (which is technically an incorrect usage)
EDC = Every Day Carry (the stuff--gun, holster, pocket knife, cell phone, pepper spray, multi tool, whatever, that you carry in your pockets and on your belt every day.)
EHOC = Empty Holster Open Carry (what some of us do in protest of the lack of reciprocity, or arbitrary permit issuance policies in anti-carry states like Maryland, California, and New York. It is just as it sounds--wearing an EMPTY holster, plainly visible.)
LEO = Law Enforcement Officer (police)
LEA = Law Enforcement Agency
IANAL = I Am Not A Lawyer (what people sometimes post at the end of a complicated legal discussion, as a sort of "disclaimer" that their opinion is worth exactly as much as you paid for it on an internet forum...)
Every state has a different name for it's CC permit or general carry/ownership license. So many people use the incorrect term "CCW" as a generic term for the permit itself. This may be convenient, but it is incorrect and inaccurate. The ONLY place "Carrying a Concealed Weapon" exists in ANY state's statute is as the definition of a CRIME. It's better (and more accurate) to use the actual acronym for the card you have. Here are a few:
IL = FOID (Firearms Owner ID)
PA = LTCF (License To Carry Firearms)
NC & VA (for non-residents) =CHP (Concealed Handgun Permit)
VA (residents) = PCCH (Permit to Carry a Concealed Handgun)
MD = PCH (Permit to Carry a Handgun--these are SUPER rare, and generally you can't get one unless you are rich and well-connected)
FL = CWFL (Concealed Weapon or Firearms License)
NH = PRL (Pistol/Revolver License)
UT = CFP (Concealed Firearms Permit)
Here is a comprehensive list, complete with pics of the actual permits:
http://www.usacarry.com/concealed-carry-permit-examples.html
And here are a few acronym/abbreviation definitions that are more for your entertainment, than linguistic accuracy:
TSA = Total Sodomy Agency / Traumatic Search Agency / Totalitarian Security A$$hats / Tremendously Stupid A$$holes
BATFE = Bringing Anarchy Through Federal Expenditures / Bastard Authoritarians Tromping Freedoms Everyday
If there are other acronyms or abbreviations you don't know or understand, please PM me, and I'll update this list...