I was referring to this, actually: https://www.nytimes.com/2017/10/10/us/politics/trump-nfl-jemele-hill.html

"WASHINGTON — President Trump threatened on Tuesday to use federal tax law to penalize the National Football League over players who kneel in protest during the national anthem, but the White House later backed off, saying he was only making a point.

Escalating a political fight that has resonated with his conservative base, Mr. Trump said Congress should eliminate a law that allowed the N.F.L. central office to avoid paying taxes as a nonprofit entity. “Why is the NFL getting massive tax breaks while at the same time disrespecting our Anthem, Flag and Country?” he wrote on Twitter. “Change tax law!”"