Do you mean this list?
ARC
Arc - mfg of small, durable, bright LED lights. "smallest and brightest"
Arc LS - Luxeon Star LED light from Arc
Arc SLS - A Second Quality Arc LS
Arc LE - Limited Edition Arc AAA with a white SB1 LED and natural HA III finish
Arc AAA - Standard Arc AAA LED flashlight
Arc CPF - CPF version of the LE. Blue case and special engraving, otherwise same as Arc LE
Turquoise EV - Brightest 5mm turquoise currently available (though nobody seems to know what "EV" stands for
Gransee (Peter) - Mr. Arc
Surefire
Surefire - mfg of high-end tactical and executive lights
LOLA - Surefire designation for Low Output Lamp Assembly
HOLA - Surefire designation for High Output Lamp Assembly
LOTC - Lock Out Tail Cap
ARB - Anti-roll bezel (hex shaped)
SIB ?? - Shock Isolation Bezel
E2(e) - Surefire executive series 2-cell 6v light
PK (Paul Kim) - Mr. Surefire
Batteries
N - 1.5V
AAA - 1.5V
AA - 1.5V
A - 1.5V
123 - 3V (originally for cameras, now used in high-performance torches as well)
Li - Lithium
Li-Ion - Lithium Ion
Nicd/Nicad - Nickel Cadmium
NiMH - Nickel Metal Hydride
General (light specific)
CPF - Candle Power Forums (where you are RIGHT NOW!)
NV - Night Vision
LEO - Law Enforcement Officer
LS - Luxeon Star LED]
LS/O - Luxeon Star LED with optics
LS HD(LD) - Luxeon Star LED High Dome (Low Dome)
LI - Lambda Illuminator. 2-AA Legend-based Luxeon Star mod
PT - Princeton tech (mfg)
UKE - Underwater Kinetics (mfg)
HA - Hard Anodized
EDC - Every Day Carry
GITD - Glow In The Dark
HID - High Intensity Discharge
DB - Double Barrel (side-by side battery compartment light)
mod - modification or moderator depending on context.
LED - Light Emitting Diode
FED - Flame Emitting Diode (Don't try this at home please!)
WA - Welch-Alleyn (bulb/lamp manufacturer)
Not specific to this site, but fun nonetheless
FAQ - Frequently Asked Questions
LOL - Laughing Out Loud
ROTFLMAO - Rolling On The Floor Laughing My A** Off
FUBAR - F'ed Up Beyond All Recognition
SNAFU - Situation Normal, All F'ed Up
IMHO - In My Humble Opinion