In 1970, the NFL wanted to charge Topps for the use of their logos. I also think Topps was not allowed to use NFL logo (sheld) also. The National Football League copyrighted the word NFL. However, it appears they did not copyright the words AFC and NFC as those words appear on the 1972 Topps set. I have the 72 set and on Chesters card the letters NFL appear on the ball Topps made the N into a W and the F into an E and the L into a D. On Cards 174 (Greg Landry) and 222 (Errol Mann) Topps also blurred the wording on the Ball. Around 1974 or 1975 the NFL sold the use of its logos and name to Fleer. What is also interesting s that today there is a case before the Supreme Court in which the NFL want the court to decide if the NFL is one entity or really 32 different entities. If the NFL wins it wll probably cost fans more money to watch NFL football games (and probably will trickle down and cost us more money to by cards)
Thanks for filling in the blanks, John.