On both 1992 Topps and Topps Gold football cards, there are several variations on the back of the card, where the copyright line appears.
Here is the front and back of Herschel Walker's Gold card:
If you look on the bottom left of the card back, you'll notice a capital letter, C, right under the Topps logo.
Here it is blown up:
However, there is another variation in which there is an asterisk to the right of the C. See below: