Filmmaker Spike Lee is promoting a planned rally for free-agent quarterback Colin Kaepernick.

Lee tweeted an advertisement for the rally, scheduled for Aug. 23 outside the NFL’s headquarters in New York. The ad misspells Kaepernick’s name, omitting the first “e.”

Lee said on Twitter he didn’t organize the protest, but that he supports Kaepernick and “his stance on the injustices in the USA.”

Several civil rights groups are organizing the rally.

Kaepernick, formerly of the San Francisco 49ers, became a topic of national conversation last year for choosing to kneel instead of stand for the national anthem, citing police violence and social injustice against minorities. He parted ways with the 49ers in March and hasn’t been signed by another team.