Here are some of the terms and abbreviations you may see here or on other couponing sites.
Blinkies: The coupons dispensers with the little blinking lights
BOGO: Buy one get one free. Usually... terms following it may indicate half off, etc. Other versions may be B1G1, B2G1, etc.
CAT: A catalina is a coupon that prints out of that little machine next to receipt printer. You may receive coupons based on what you buy. You may receive notice of upcoming promotions. Usually the best ones are OYNO coupons. They are called CATs because The Catalina Marketing Company produces them.
DND: Do not double
GM: The General Mills Sunday coupon insert
MIR: Mail in rebate
OYNO: On your next order. Usually referring to Catalinas
OOP: Out of pocket
P&G: Proctor and Gamble. Usually referring to the P&G Sunday coupon insert
Peelie: Coupons that are stuck on the product.
RP: Red Plum Sunday coupon insert
SCR: Rite Aid's Single Check Rebates
SS: SmartSource Sunday coupon insert
wyb: when you buy
ymmv: Your mileage may vary... as in this deal may or not work for you
+UP: Rite Aid's +UP rewards. A coupon good toward a future purchase, printed at the bottom of your receipt.
I think that covers most of it...