Here are a couple of the roughing rules. (Sorry if I've inappropriately brought language into an otherwise pleasant debate.)
Article 12 Because the act of passing often puts the quarterback (or any other player attempting
a pass) in a position where he is particularly vulnerable to injury, special rules against roughing
the passer apply. The Referee has principal responsibility for enforcing these rules. Any physical
acts against passers during or just after a pass which, in the Referee’s judgment, are
unwarranted by the circumstances of the play will be called as fouls. The Referee will be guided
by the following principles.
[snip]
When the passer goes outside the pocket area and either continues moving with the ball (without
attempting to advance the ball as a runner) or throws while on the run, he loses the protection
of the one-step rule provided for in (1) above, but he remains covered by all the other special
protections afforded to a passer in the pocket (Numbers 2, 3, 4, 5, 6, and 7), as well as the
regular unnecessary-roughness rules applicable to all player positions. If the passer stops behind
the line and clearly establishes a passing posture, he will then be covered by all of the special
protections for passers.