NFL officials will be paying close attention to contact between defensive backs and receivers during the 2014 season. (PAUL BUCK/EPA)

Illegal contact between receivers and pass defenders will be a “major point of emphasis” for game officials during the upcoming 2014 NFL season, according to the league’s officiating video to be shown to players during training camps.

“Contact between receivers and defensive players prior to a pass will be a major point of emphasis this season,” a narrator says during the nearly 12-minute video to be shown by officials during their annual camp visits.

The NFL has been in the most passing-friendly era in its history for a decade, thanks in part to the sport’s 2004 crackdown on existing rules prohibiting clutching-and-grabbing tactics by defensive backs on receivers more than five yards beyond the line of scrimmage.

Quarterback Peyton Manning, then with the Indianapolis Colts, set a single-season NFL record with 49 touchdown passes in the 2004 season after illegal contact in the secondary was made a point of officiating emphasis. New England’s Tom Brady broke Manning’s record with 50 touchdown passes in 2007, and Manning re-set the mark with 55 last season for the Denver Broncos.

Seven of the eight 5,000-yard passing seasons by NFL quarterbacks have come since 2008 — including four by Drew Brees of New Orleans and one each by Manning, Brady and Detroit’s Matthew Stafford. Prior to 2008, there had been one 5,000-yard passing season in league history, by Dan Marino for the Miami Dolphins in 1984.

Manning also set the single-season record for passing yards last year with 5,477. But he and the Broncos were overwhelmed by the defense of the Seattle Seahawks in the Super Bowl. Seattle’s defensive backs are known for their physical play.

NFL defensive players repeatedly have complained in recent years that the league has made stopping high-powered opposing offenses nearly impossible with rules penalizing illegal contact in the secondary and hits on players deemed to be defenseless, such as when a pass puts a receiver in a vulnerable position — leaping for a throw, for example — in the middle of the field.

“Defenders cannot initiate contact with eligible receivers more than five yards from the line of scrimmage when the quarterback is in the pocket with the ball,” this year’s NFL officiating video says. “The covering official will recognize the contact and then look back to the quarterback. If he is in the pocket with the ball or in the process of releasing it, it will be a foul for illegal contact.

“A defender is entitled to an established position on the field beyond five yards. If he has that position, he can use his hands or arms only to defend himself from impending contact by a receiver. The defender cannot slide over and create contact with a receiver beyond five [yards]. Grabbing the jersey or any other part of a receiver’s uniform prior to a pass is defensive holding and will be called regardless of whether or not the official deems that the grab impeded or restricted the receiver.”

Receivers also will be monitored closely and penalized if they shove defensive backs to try to make a catch, the video says.

“Receivers can use their hands or arms to ward off contact initiated by a defender, but cannot push off to gain separation in an effort to catch a pass,” the narrator says in the video. “Game officials will pay particular attention to actions at the top of the route such as these.”

This is the first time in seven years that the NFL has made enforcing illegal contact in the secondary a point of emphasis for game officials. After the 2004 crackdown, it remained a point of emphasis from 2005 to 2007. This is the first time since then that it has been a point of emphasis to officials.

The officiating video emphasizes player safety rules and other changes, including the referee being in contact with the league office during instant replay reviews and the preseason experiment with a longer extra point.

“There are two things we want to accomplish,” Troy Vincent, the NFL’s executive vice president of football operations, tells players during the video. “First, the rules ensure the safety and the administration of the game. The healthier you are, the longer you play and the more value you have to your team and your teammates. And in some instances, the rules may cause you to alter your play. But they are in place to protect you from unnecessary risk.

“Second, we want to keep you on the field. As a former player, there are few things as frustrating as being fined for something you didn’t realize was a fineable offense or worse, having to sit and watch someone else play your position. If you have a clear understanding of the rules, your chances of staying on the field are higher. That’s best for you, your team and the league.”