Wide receiver Plaxico Burress said if the number of on-field officials were increased to, say, 10 from 7, players would get away with less.

Tagliabue said that effective immediately, all on-field officials would confer on calls in dispute.

That such an idea even surfaced indicates the gulf in negotiations between the N.F.L. and its on-field officials.

Referees are encouraged to continue developing their knowledge and skills throughout their careers as on-field officials.

They may call down to the on-field officials to stop play if they need extra time to make a review.

From the 2004 to the 2012 seasons, he served as an on-field official for the league, wearing uniform number 57.

He alone decides which plays will be reviewed and has the final say on whether on-field officials made the proper call on matters of possession.

Early games did not use any on-field officials but disputes between the players would be referred to a committee member.

The on-field officials ruled the pass complete and good for a first down.

He assumed the devil's role from the on-field officials he was judging.