[BigRygg]

While working chain crew this year, I've seen the following techniques:

The receivers would come out talking to the wingmen, telling them "I'm on the line" or "I'm off the line." The official (both sides of the field) would then help them out if need be.

Also, when the receiver would look over, the officials simply would hold up their backfield arm straight toward the ball (indicating "on the line") or parallel with the sideline toward the backfield (indicating "off the line"). Granted, this also is for their counterpart on the other side of the field to read, but the kids knew how to read it as well.

If the kids didn't see what they liked, they moved themselves until the officials changed their arm position.