Here are some helpful coupon terms and abbreviations.
OOP- Out of Pocket- The actual amount you pay in the transaction, whether it be cash, check, credit or debit. It does not take in to account any rewards you get back.
CRT- Cash Register Tape- Usually refers to coupons printed on the bottom of your receipt.
RR- Register Rewards- The Walgreens rewards. They are printed out after you do a transaction and usually only last a week. Walgreens, at this time, does not allow you to use RRs on another RR deal. If you do, the new RRs will not print.
ECB- Extra Care Bucks- The CVS rewards. They print on the bottom of your receipt after a CVS transaction. ECBs last 4 weeks and you can use them to pay for a transaction that includes items that will earn you additional ECBs. In addition, you can earn extra ECBs each quarter. These print out from the red coupon machine in each CVS.
UPR- Up Rewards- The Rite Aid rewards. They print on the bottom of your receipt and the expiration date varies from a week to longer. Like CVS, you can use them on items that will earn you more UPRs.
IVC- Instant Value Coupon- A Walgreens coupon that you can find in their monthly savings booklets. They are store coupons and so they can be stacked with manufacturers coupons.
SS- Smart Source coupon insert
RP- Red Plum coupon insert
P&G- Proctor & Gamble coupon insert
MIR- Mail in Rebate
BOGO-B1G1- B1G1F- All are variations of "buy one, get one free"
CAT- Catalina- Coupons that print after your receipt (Target does a lot of catalina coupons). They are often store coupons, though if they say "Manufacturer" on them, you can use them at any store.
WYB- When you buy
These are the basics you'll encounter on couponing sites! :)