Ive been collecting hockey cards for about 12 years now, and with the growth of online trading, a lot of new terms and abbreviations have been introduced into our hobby.  This is in no way a complete guide, but Ive done my best to include all the lingo Ive heard in my short time in the hobby.  I hope this helps out!

AU - Autograph

Auto - Autograph

RC - Rookie Card

BAP - Be A Player

ITG - In The Game

OPC - O-Pee-Chee

UD - Upper Deck

Dupe - Duplicate, Double

HG - High Glossy

Jsy - Jersey

Swatch - Jersey Swatch

Emblem - Swatch of Patch from Game Used Jersey

Patch - Premium Swatch from Jersey

BV - Book Value

LMK - Let Me Know

MOJO - A Big Pull from a pack/box of hockey cards

HOF - Hall of Fame

AP - Artist Proof

SP - Short Print

L - Limited

XL - Extra Limited

XSP - Extra Short Print

SSP - Super Short Print

JSY/AU RC - Autographed Rookie Jersey Card

EXCH - Exchange Card / Redemption Card

CL- Checklist

ERR - Error Card

NNO - No Number

XRC - Extended Rookie Card

MT - Mint

NRMT-MT - Near Mint - Mint

NM - Near Mint

EXMT - Excellent Mint

EX - Excellent

VG - Very Good

G - Good

F - Fair

P - Poor