This topic has been added to the todo-list. Reason: needs more info.

Who owns the Klingon language?

It has never been really clear who owns the rights on the Klingon language or what exactly that means after all. There has never been any legal procedure or discussion about that, so the question has always left unanswered. Even the Axanar lawsuit of 2016 did not give a clear answer, although Paramount has mentioned that the language is their property in a long list of items created for Star Trek.

Facts

General

"Star Trek and related marks are trademarks of CBS Studios Inc." (1)

The word "Klingon"

The listed owner on the US trademark office is CBS Studios Inc.
There are three entries for the word "Klingon":

"toy spaceships; model kits for building toy spaceships" (2)
"computer game software recorded on CD-ROM" (See Star Trek: Klingon) (3)
"wine" (See Wine) (4)

The Klingon Dictionary

The first and second edition of TKD say "Copyright © 1985 by Paramount Pictures" and "This book is published by Pocket Books [...] under exclusive license from Paramount Pictures". Newer editions mention the copyright of CBS.

This makes clear that there is a copyright on the book, i.e. The Klingon Dictionary.

Marc Okrand

The creator of the language and author of the dictionary, Marc Okrand, might actually own the rights to the language. His creation of the language was a part of a work for hire, but he was actually hired to create lines for the movie, so the producers might only own the copyright to the lines he provided and not the language as a whole. However, since Paramount and CBS hold the copyright to The Klingon Dictionary, Dr. Okrand may not have the right to create a new Klingon Dictionary.

The Axanar complaint

The creators of the Axanar movie project have been sued by Paramount for Copyright infringement in 2016. During this legal procedures, all of the infringements were listed and among them was the Klingon language. Critically, this not a direct claim by Paramount that they believe they hold copyright on the language, since the law suit only claims that the unique combination of elements listed is what makes the Axanar movie an infringement. So far, the court has rejected even considering whether Paramount might have a claim to copyright of the language itself. Outside of court Paramount seems to claim that they own the language, but it remains open in what range; That means: what can you do with it and what not? In this case, the complaint is focussing on the production of an entire movie which uses "hundreds" of copyrighted and non-copyrighted items, and the klingon language is only one of them.