In Maine, we ask our wings to : (1) Fist into backfield if WR is off the LOS; (2) Fist with 2 fingers wagging if twins are both off; (3) No signal if WR is on LOS, but tapping top of cap if he's covering a potential eligible receiver. ^talkR & U will read the wings signals and respond by : (1) Giving extended fist indicating 11 players on A; (2) Followed by "thumbs up" to indicate 7 man line; (3) If slot or TE is covered, tap cap and discretely point. Illegal formation is nearly always called by R & U. If umpire rubs his belly after play is completed, that indicates he is in need of a
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I'm with Ralph for 1, 2.
As for (3:) 'hand to the cheek' for covered round these parts. BUT, in my opinion, that is H/L primarily to handle. Sure, it's good for U, and/or even R too, to know (and put a 'hand to the cheek' too so everyone is on the same page)
Ultimately though, (my opinion) someone 'covered' is a H/L call.
Cant say I've ever seen "thumbs-up" for 7 on the line. - but hey, everyone is different. As long as everyone is on the same page is what is important.
IF there is a 'covered' signal that U will give, I highly recommend against pointing. - it really tips your hand (no pun). sharp coaches, like Atl, will see this immediately.
Instead of pointing, maybe just a hand to the cheek to the H/L side of the LOS the player is covered.
i.e. right hand to cheek, the guy on the right side is covered (and is only applicable to the wing to the right side of U).