NFHS - TE/DE Block Below the Waist -Keys/communication
 

Double tight end formation. TE/DE are outside the FBZ.

My understanding, LJ/HL have this key and would be responsible for making the call on a block below the waist by the defense or offense.

My question, how do you communicate between the R and LJ/HL to indicate the TE/DE are outside the FBZ or inside the FBZ? HL/LJ may not be able to ascertain if the pair's location reference the FBZ

I worked a game where the TE/DE were moving in/out depending on the play.

There is none. 5 man mechanics, whichever wing has the TE, it his call.
Err on the side of he's in the zone unless he is obviously not.

This is where O2O (radios) is an invaluable tool for officials.

H/L: Is TE in blocking zone
R/U: No
H/L: sees low block, throws flag



Alternatively (and this can work without O2O if your local area doesn't allow them):

H/L: sees low block, throws flag
* down ends *
H/L: reports foul to R and U.
R/U: That TE was in the blocking zone, so we need to pick up the flag
H/L: picks up flag.

Seems to have worked pretty well when a wing or deep official observes an eligible receiver in the proximity of an incomplete legal forward pass deemed to have been intentionally in-completed. Simply adds relevant information to the penalty decision.