fanspeak
Noun
Meaning
(informal) The jargon used by science fiction fans.
(by extension, informal) The jargon used by fans of any genre of fiction or popular culture in general.
Source: en.wiktionary.orgExamples
Fans around the world knew Ackerman by three letters "4sj" or even two: "4e" for "Forry.") Fanspeak is rich with abbreviations and concatenations.