What is the Tinker Test and when does it apply?

Currently, I have a bill-writing project assigned for my government class. I’ve already written and presented my bill, but two of my classmates still to present have been censored by my principal. Their topics were “Legalized Marijuana” and ironically, “Censorship in Schools.”

The principal justified his decision by stating that the marijuana bill advocated for drug use, and the censorship bill could potentially make a sexually abused student uncomfortable (he defines pornography within the bill). I’ve heard of the tinker test—does it apply to this, and if so, what could the consequences be?

My apologies for the long explanation.