something the NCAA was very picky on +/-10yrs ago:
When the QB does his leg raise to tell C to snap the ball - many QB were 'stepping into' (stepping the foot forward) to signal...which is illegal shift. (moving fwd at the snap, right?)
More HS QB are guilty of this than not. ...but since NCAA clamped down on this 10+/- yrs ago we dont see it much anymore at the college (or NFL) level.
With that, next few HS games you fellas see, just note if you see that QB move that foor fwd....maybe a good discussion with your local assns....