I have put this list together with the help of a few other members this afternoon for the use of any member in need of a definition to a term used on this site. If I have left any thing out please feel free to reply or Pm me and I will add it.
6i = 4 cylinder Mazda6
6S = V6 Mazda6
AAP- Accelerator Pedal Position
ABM/ Air Box Mod = The process of taking unwanted parts off the stock engine air box out to let the engine breath better
AEM = Advanced Engine Management(Brand Name)
AFAIK = As Far As I Know
AJ = Mazda 6 with 3.0l V6
AP = AccessPort by Cobb
AR = After market Rims
AT = Automatic Transmission
ATR = Access Tuner Race, tuning software for the AP
ATX = Auto Trans axle
Axle-back = Exhaust from rear axle
AWD = All Wheel Drive
BAT - Boosted Air Temp
BOV = A turbo engines blow off valve
BT- Big Turbo
Bump = Brings post to top
BPV = ByPass Valve
BSD = Balance Shaft Delete
BSF or B/S = Buy/Sell Forums
BTW = By the way
Cat back = An exhaust system that starts at the catalytic converter.
CAI = Cold Air Intake
CCC = Combustion Chamber Cleaner
CEL = Check Engine Light
CF = Carbon Fiber
Cleansweep = A audio device made by JL Audio (Brand Name)
DDE = Daylight Demon Eyes (Halos, Angel Eyes, etc)
CD = Cross Drilled Rotors
CP-E = Custom Performance Engineering(Brand Name)
CRP = Commonly Reported Problem
CSC = Centrifugal Supercharger
CTS = Coolant Temp Sensor
DIY = Do It Yourself
DYI = Do Yourself Install
EBCS - Electronic Boost Control Soleniod
ECU = Engine Control Unit
EGR = Exhaust gas recirculation
EGT- Exhaust Gas temp
EMS = Engine Management System
EWG- External Wastegate
FMIC = Front Mount InterCooler
FOB = The flip out key that your Mazda most likely uses
FP = Fuel Power additive
FS = For Sale
FSM = Factory Service Manual
FT = For Trade
FTW = For The Win
FWD = Front Wheel Drive
GB = Group Buy
GC = German Casterol(green 0w-30 engine oil)
HID = High Intensity Discharge light
HU = Head Unit
IBTL = In Before The Lock
I.C.E. = In Car Electronics/Entertainment
IIRC = If I Recall Correctly
IMO = In my opinion
IAT - Intake Air Temp
IM- Intake Manifold
IRS = Independent rear suspension
IWG- Internal Wastegate
JDM = Japan Domestic Market
JK = Joke or joking
L3 = Mazda 6 with 2.3l I4
LED = Light-Emitting Diode
LHD = Left Hand Drive
LMAO = Laugh My Ass Off
LOC = Line Output Converter
LOL = Laugh Out Loud
LSD = Limited Slip Differential
MAF = Hot Wire Airflow Sensor
MAFci = CP-e MAF Chip/CAI combo pack
MF = MagnaFlow(Brand Name)
MPI = Multiple port injection
MPS = Mazda Performance Series
MRI = Mazda Recall Information
MS/MS6 = Mazdaspeed
MT = Manual Transmition
MTX = Manual Trans axle
NA = North American
NOS = Nitrous Oxide Systems(Brand Name)
NSFW = Not safe for work
NX = Nitrous eXpress(Brand Name)
OCC = Oil Catch Can
OEM = Original Equipment Manufacturer
OP = Original Poster
PCV = Positive crankcase ventilation
PI = Performance increase
PICS = Pictures
PITA = Pain In The Ass
PNP- Plug n' play or Ported and Polished
PM = Personal Message
PO = Previous owner
POS = Piece of Sh*t
PT- Part throttle
PWNED = To be called out or simply made a fool of by another member of the board (owned).
PVO = Performance Vehicle Operations
RB = Racing Beat
RHD = Right Hand Drive
RMIC = Rear Mount Intercooler
ROFL = Rolling on floor laughing
RPM = Revolution Performance Manufacturing(Brand Name)
RSB = Rear Sway bar
R/T = Road/Track
RTFM = Read the Freaking Manual!(Owners manual, FSM, or Instructions manual for part install)
SB- Stand Back (tuning device)
SC = Super Charged
SMIC = Side Mount InterCooler
SOL = S&@$ outta luck
SOTP = Seat Of The Pants
SR = Stock Rims
SRI = Short Ram Intake
SRT = Street and Racing technology
STF = Search the forum
STFU = Shut the f&#^ up
STS = Short Throw Shifter
SU = Streetunit.com
TB = Throttle Body
TBD = To be determined
TC = Turbo Charged
TCM = Transmission Control Unit
TIA - Thanks in advance
TMIC = Top Mounted InterCooler
TP- Throttle Position
TPS = Throttle Position Sensor
Troll(ing) = A member that intentionally lurks around looking to act like an ass
TSB = Technical Service Bulletin
TT = Twin Turbo
ttt = Brings post to the top (To The Top)
TTUW0P = This Thread Useless Without Pics
UCA/LCA = Upper control arm / Lower control arm
UOA = Used Oil Analysis
WGA - Wastegate Actuator
WGDC = Waste Gate Duty Cycle
WMI (or W/M) - Water Methanol Injection
WTB = Wanted to buy
WTF = What the F#@&
WTT = Want to trade
WOT = Wide open Throttle
And not to forget
GRMFMTL = Give Rob $ for making this list