With thanks to team photographers and Getty Images, please enjoy photos that have officials in the frame. Note how the officials are carrying their electronic whistles (either tied to their belt loops or tied with a wrist lanyard).
From team photographers (click on a photo to begin gallery):
Perry Paganelli ready to judge a field goal (Green Bay Packers).
Note Tony Michalek holding his electronic whistle that is strapped to his belt. (Green Bay Packers)
Jeff Seeman (Green Bay Packers)
Rick Patterson (Las Vegas Raiders)
Down judge Mike Carr and side judge Don Willard (Green Bay Packers).
Jimmy Russell (Las Vegas Raiders)
Shawn Smith (Buffalo Bills)
Todd Prukop and Tony Corrente conduct an old-fashioned coin toss (Dallas Cowboys).
Jeff Seeman (Green Bay Packers)
David Meslow (Green Bay Packers)
Dan Ferrell (Los Angeles Rams)
Fred Bryan (Kansas City Chiefs)
Mike Carr (Green Bay Packers)
Bill Vinovich (Green Bay Packers)
Fred Bryan (Kansas City Chiefs)
Alex Kemp and Greg Bradley (Detroit Lions)
Dino Paganelli (New York Jets)
Perry Paganelli (Minnesota Vikings)
Tom Symonette (Indianapolis Colts)
Blakeman Crew (Kansas City Chiefs)
Tony Michalek (Green Bay Packers)
Mark Hittner (Houston Texans)
Tom Hill (Seattle Seahawks)
Don Willard (Minnesota Vikings)
David Meslow (Green Bay Packers)
Adrian Hill (New England Patriots)
Brad Rogers (Washington)
Matt Edwards (Detroit Lions)
Umpire Paul King. Note his electronic whistle. It is strapped to his left wrist and he's carrying it in his hand. (New England Patriots)
Walt Coleman, IV (Washington)
Bill Vinovich (Green Bay Packers)
Michael Banks (Houston Texans)
Tony Corrente (Dallas Cowboys)
Ron Torbert (Baltimore Ravens)
From Getty Images:
Referee Adrian Hill
http://gty.im/1272423059
Officials Ron Torbert and James Coleman kneel during the National Anthem. Down Judge Jim Mello is in the background.
http://gty.im/1272337744
Line judge Mark Perlman
http://gty.im/1272337720
Referee Ron Torbert
http://gty.im/1272336864
Down judge Derek Bowers
http://gty.im/1272313972
Referee Shawn Hochuli
http://gty.im/1272313601
Referee Jerome Boger and down judge Julian Mapp.
http://gty.im/1272305154
Side judge Jonah Monroe
http://gty.im/1272305402
Down judge Sarah Thomas
http://gty.im/1228500133
Umpire Ramon George. Note the electronic whistle tied to his belt.
http://gty.im/1228499861