A hold is a hold...

[MJT]

Comments to players like, "I need to see your fingers, don't get your arms on the outside of him, and carefull of hooking him," can go a long way when followed up by, "that was pretty borderline." This is maybe a little more suttle way of saying the same thing as "it would have been a hold if the ball came this way." I agree about taking to the players to be a good preventative official.