From 1992 (or thereabouts): a fan created guide to the Tenctonese language, as published by Britain's ALIEN NATION APPRECIATION SOCIETY.
File under: labour of love.
This took the basis of the spoken and written language introduced in the feature film but refined and expanded for the Fox weekly series incarnation, and tried to make sense of it.
To the show's credit, it really did sound like it was an authentic language... but I'm still not sure I would be inclined to try and make sense of it.
This was a black & white A5 publication with colour cover. The society was run by Pete Chambers who was, latterly, rewarded for his attempts to keep the show alive (after the fledgling FBC shifted their early schedules - which only amounted to a few hours per week - from expensive one-hour dramas to cheaper to make sitcoms) with a guest spot (as an alien, of course) in one of the five TV movies which reunited the cast (and production team) a good half-decade after the show was canned.
I was a member of the group for years but - stupidly - didn't hang onto any of the regular A5 newsletters.