Despite their best efforts, the Cowboys' helmets will not feature a decal supporting Dallas police officers this season.

According to Brandon George of the Dallas Morning News, the NFL denied the team's request for permission to include a decal reading "Arm In Arm" on their lids for the upcoming season. That decal, which the team has been wearing on its helmets during training camp, is in support of Dallas Police and the officers killed in July's sniper attack.

After hearing back from the league on Wednesday, Cowboys vice president Stephen Jones gave the following statement, as reported by George.

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"Everyone has to be uniform with the league and the other 31 teams. We respect their decision," said Jones."There are so many wonderful, wonderful causes, the league has to be careful. If you allow one, then what do you do about every team that has a great reason to have something on their helmets?"

The NFL has unapologetically enforced it's strict uniform policies for years. Just last season the league denied the request of Steelers running back DeAngelo Williams to wear pink gear all season in honor of his mother, who passed away from breast cancer. Williams was also fined for having the message "Find the cure" printed on his eye black during a game.

The Cowboys' "Arm In Arm" decal promotes unity between members of the Dallas community and its police officers. On the opening day of camp, the team -- joined by the Dallas police chief, the city's mayor, and family members of the slain police officers -- walked onto the practice field with their arms intertwined and unveiled the decal in a ceremony honoring the officers lost.