Conversation so far:
Who initiated the ban?
Joseph Carr made it one of his first goals as league president to impose a strict ban the use of college football players.
When was the APFA college player ban initiated?
The ban was initiated around 1921.
How did Carr enforce the APFA college player ban?
Players lost their amateur status and were barred from further college football participation.

Question: What else did he do to enforce the ban?
Self-contained rewrite: What else did Joseph Carr do to enforce the APFA college player ban?