Blocking

Blocking is allowed from below the neck to above the waist ("within the frame"). NO cut blocks allowed; no shoulder blocking; no blocking below the waist.

As per regular football rules, downfield blocking before the ball leaves the quarterback's hand as a forward pass is a penalty.

Ineligible linemen can move downfield but will be considered illegally downfield if the they move across the line of scrimmage before a forward pass does. They can move downfield if the forward pass never crosses the neutral zone though (e.g. a screen pass).

Downfield blocking immediately negates the Four Mississippi count.