The PC+ Coupon Codes will be the same format every month.
December: 12-17PlatClub or 12-17Save6
January: 01-18PlatClub or 01-18Save6
February: 02-18PlatClub or 02-18Save6
01-18Save6 = This coupon is for $6 off of a $18 purchase; on anything in the store. This excludes New Releases, Gift Cards, FastGrab, and PC+ memberships.
01-18PlatClub = This coupon code is good on DAZ Original items only. Excludes Platinum Club items, Gift Cards, FastGrab, and PC+ memberships.
You can recognize a DAZ Original by looking for "Artist: DAZ Originals" on the product page to the right of the promo image. If another artist is listed after DAZ Original, it is still a DAZ Original product.
The coupons expire every month. This means they cannot be rolled into the following month. You use them, or lose them.
The coupons are updated according to UTC (Universal Time Coordinated). So, it is possible they can expire early, as there is about a 5-6 hours difference.