Coaches box

[zm1283]

How are football crews instructed to enforce the sideline rule? (Don't know the technical term for it) Does it vary by association, state, or just whatever crew happens to be working? I'm asking because over the course of this season, we have had crews that don't seem to care where anyone is (Several coaches in the box at the snap) and crews like last week that throw the flag for a warning and then penalize for when anyone has their toe touching the line. It just seems like this is enforced very inconsistently.

I guess it is kind of like basketball. Some officials let the HC wander to the end line and some enforce the box pretty strictly.