The vote, per Jenny Vrentas of Sports Illustrated, also prohibits contracts from including right-to-match clauses or compensation requirements if an assistant leaves for a coordinator job.
Teams were previously able to block assistants from interviewing for positions that could be deemed "lateral moves," and assistant-to-coordinator transitions previously fell under that umbrella. NFL teams are not allowed to prohibit assistants from interviewing for head coaching positions.
Coordinators will still not be allowed to leave their team for another NFL coordinator position without seeking permission.
The changes are part of an initiative to increase diversity on NFL coaching staffs and high-level positions. There are currently only four minority head coaches and two minority general managers. Roughly 70 percent of NFL players are black.
"We believe these new policies demonstrate the NFL Owners' commitment to diversity, equity and inclusion in the NFL," Steelers owner Art Rooney II said. "The development of young coaches and young executives is a key to our future. These steps will assure coaching and football personnel are afforded a fair and equitable opportunity to advance throughout our football operations. We also have taken important steps to ensure that our front offices, which represent our clubs in so many different ways, come to reflect the true diversity of our fans and our country."
The league also made changes to the Rooney Rule, requiring teams to interview two external minority candidates for head coaching vacancies and one minority candidate for coordinator positions and high-level front-office positions.
A resolution that incentivized teams to hire minority candidates by improving their draft position was voted down.