The Field - Sidelines

Rule 9-1-6:

While the ball is in play, coaches, substitutes and authorized attendants in the team area may not be between the sideline and coaching line or on the field of play.

Enforced as a dead ball foul (succeeding spot).
1st - 5 yards
2nd - 5 yards
3rd - 15 yards

In addition, Rule 9-1-5a states:

No substitute, coach, authorized attendant or any person subject to the rules, other than a player or official, may interfere in any way with the ball, a player or an official while the ball is in play.

Enforced as a dead ball foul (succeeding spot) - 15 yards

In the real world, we work with the coaches and ask the same from them. The rules aren't enforced to keep them from doing their job, but rather for everyone's safety. In 2007, the enforcement for the 1st flag was a warning. In 2008, the warning was replaced with a 5 yard penalty for the 1st flag. Flank officials work "off the field" and need the room to do their job and having coaches and players in the restricted zone creates a real safety issue. Picky? Hardly, just ask these officials.
Fort Worth Star Telegram:

By TROY PHILLIPS As if officiating football games in Texas wasn't difficult enough, now comes a case navigating the San Antonio district courts that could have a chilling effect on the men in zebra stripes. On Oct. 27, 2006, a workers' compensation insurance carrier for the San Antonio school district filed a $10 million lawsuit against five officials....

Here's what can happen.



This is not the way to handle sideline control.
If coaches are on the field, throw the flag.

The Field - Limit Lines

When is the last time anyone discussed Limit Lines on a football field? It's an obscure term in the rule book, but when there are serious consequences, it's brought to the forefront. Last season's Marshall vs Houston game is a prime example.

Rule 1-2-3a and b specify limit lines and Rule 1-2-8a and b deals with markers, obstructions, and safety in the playing enclosure. If there is a hazardous obstruction within the limit lines, the referee is responsible for ordering it's removal. If outside the limit lines but within the playing enclosure, the referee notifies game management. Game management has responsibility for determining corrective action.

In the video note the metal carts being stored behind the end line.