Welcome to Labor Law 101.

Colin Kaepernick has just filed a grievance with the National Football League over alleged collusion by team owners to keep him from playing, in retaliation for his advocacy of racial justice.

Whatever the outcome, this represents the next round of the fight after NFL Commissioner Roger Goodell urged NFL owners to make their players to stand during the national anthem.

How to stand with Colin Kaepernick

Read Sports Illustrated's analysis of how the case might go.

Read our background on Colin Kaepernick's treatment by the NFL and our nation's current leader.

Follow #TakeAKnee, #TakeTheKnee, #StandWithKap, and #IStandWithKap on Twitter for updates.

Sign this petition showing your support for NFL players who take a knee against police brutality.

Donate to some of the groups Colin Kaepernick has already given nearly $1 million, including United We Dream, Justice League NYC's War on Children, Dream (formerly RBI Harlem), and Coalition for the Homeless.