[waltjp]

Exactly, Brett. My old R and I (when I was a U) used to disagree over this topic. He insisted that our wings needed to use all kinds of signals to indicate who was on and off the line because "Walt and I need to know that."

My argument was this - once the snapper is in position over the ball and especially after the rest of the line is in place I can't divert my attention from the ball to look at the wings to see who is and isn't on the LOS. For one, they're not my responsibility. Two, they could shift after I turn away from them. Three, there may be some sort of false start or snap infraction while I'm looking away.

I'll check to see if I have 5 lineman numbers and when I find then I'll make sure they don't go down field on a pass that crosses the LOS. If you have an eligible number that's covered then you make the call.