CU - Copper D/S - Double Struck or Strike O/C - Off Center So you have a 1982 Large Date Copper Cent that is Double Struck. The 2nd Strike is 90% Off Center MS stands for Mint State with a rating of 64 RD stands for Red - the color of the Cent
When NGC runs out of room on their label to describe an error coin such as yours, they need to use initials. Also, you might see B/S - Broadstruck