Fandom Tic

Those weird things and ideas that just keep cropping up in fandom, over and over again. Like Fanon, but not. The little schticks that make it obvious what one enjoys, from Firefly Fen commenting on things being "shiny", to those accepted mandatory scenes that every fanfic must include for it to be a true story of the fandom.

The sacred cows that can either be worshiped, or turned into burgers, depending on how one feels. They can also become Shibboleths used to separate the "true" fans from the posers, at least at first. When the posers catch on, though, the Fandom Tic might become incorporated into a stereotype for that kind of Fan.

Can overlap into The Stations of the Canon.

Fan Works

 * Worm: Every fanfic must start with a "Locker scene". Every fanfic must include a power testing scene. [DESTINATION]...[AGREEMENT]....
 * Ranma ½ has had its share over the decades since fanfic writers have started going at it. Among others:  Ryoga dropping in screaming "Ranma, prepare to die!"  Akane clobbering Ranma with a Hyperspace Mallet.  And every Alternate Universe Fic has to have its own variation on the "meet the fiancees" scene.

Live-Action Television

 * Star Trek fandom in its first decade or so was distinctively marked by the fans' use of the Vulcan salute and greeting ("Live long and prosper"). This seemed to fade away, except for nostalgic and perhaps ironic use, after the premiere of Star Trek: The Next Generation.  (Although it still remains part of the "Trekkie" stereotype, along with bad pointed ears and toy phasers.)

Professional Sports

 * Name a team whose fans don't have some distinctive chant, cheer or other behavior.
 * For some bizarre reason, singing the theme song to the 1969 Pippi Longstocking TV show is a distinctive behavior of soccer fans in Europe.