What gets a player or coach penalized or disqualified for conduct?

• Unsportsmanlike conduct (confrontational or offensive behavior or language, physically or verbally abusing an opponent, coach or official): 10 yards from the dead-ball spot. Against the defense it's also an automatic first down; against the offense, a loss of down.
• Two unsportsmanlike penalties on the same player or coach in a game means disqualification, and possibly further discipline.
• Intentional physical play (intentional tackling, elbowing, cheap shots, blocking): the game is stopped and the player is ejected, at the officials' discretion. No appeals.
• Electronic communication with a player by a coach or team spectator: the team is disqualified immediately.
• Unfair acts such as the defense mimicking the offense's snap signals to confuse it, or not returning 5 eligible players to the field after halftime: an unsportsmanlike conduct penalty on the head coach.

Coaches are also responsible for the conduct of their fans and anyone in their team area.