For some reasons some jersey that have been retired have been worn again.
Nordiques: #3 Jean-Claude Tremblay, #8 Marc Tardif, #16 Michel Goulet
have been de-retired when the team moved to Colorado. Did the Coyotes do the same thing with # 9 Bobby Hull and # 25 Thomas Steen when the Jets moved to Phoenix?
Whalers: #2 Rick Ley, #19 John McKenzie
The #9 Gordie Howe was also retired in Hartford was it worn since the team moved to Carolina?
Canadiens: #4 Aurele Joliat, #16 Elmer Lach
When the numbers were officially retired the team decided to honor both Joliat and Jean Béliveau for #4 and Lach and Henri Richard for #16. Now only Béliveau and Richard hangs from the rafters.
In an unpopular move to Boston, Guy Lapointe wore Dit Clapper #5 but changed to #27 after the Bruins fans disapproved.
complete list of retired numbers:
http://www.azhockey.com/shirts.html
Is there any others?