Game Worn Jersey Patches

Patches can be used league wide like the NHL 75^th Anniversary, the 100 year Stanley Cup Patch or the NHL 2000 patch.
Teams that will host the all-star game usually have a patch. The All Star jerseys themselves may have one also.
The two teams in the Stanley Cup finals will wear a patch.
A teams anniversary. Flyers 25^th, Pens 25^th, Bruins 75^th , Panthers 5^th etc.
Patches to signify a event like Calgary 1988 Olympics, Quebec rendezvous 87, the game one patches, Hall of Fame Game patches, City related patches.
A memorial patch, Pelle Lindbergh 31, Badger Bob, Steve Chaisson 3, Barry Ashbee 4, CHS, 911 etc.
Patches for opening or closing of arenas.
Advertising patches. Mostly on Minor league teams. The Dunkin Donuts was on a New Haven Knighthawks jersey, MeiGray Group from the 2002 ECHL AS Game jerseys, and the Modell's from the Philadelphia Phantoms.