Four on the floor

[Rooster]

Third year guy here: Some officials whom I respect and I were discussing a situation where there were four players on the court during a live ball and how the practical applications should go down. I would swear that I read somewhere that it's a T to only have four on the court, but I can't find it anywhere (hence this post).

My first year I had this happen. Boys freshman game: Following a time out and after making eye contact and not counting the players well enough, we put the ball in play. You know that feeling when people starting hootin' and hollerin' because something isn't right but you don't know what it is yet? After checking to see if my fly was open I finally figured it out and when the team with four got the ball and action stalled I blew it dead and asked the coach to send in the fifth player. Everyone kinda chuckled, I was embarrassed, and we moved on without any discussion or argument.

I have looked and looked and the best I can come up with is 3-1-1. I thought I saw it in the Official's Manual but whiffed when I went back to find it. Anyone know where I can find the rule on this one?

Thanks.