10 Times Star Trek Broke Its Own Rules
5. The Klingon Language
Mark Lenard, better known for playing Sarek in the Original Series and the later films, appeared on-screen in 1979 as the captain of one of the three Klingon K'T'inga class Battlecruisers that are zapped out of existence by V'Ger.
In these scenes, he speaks a Klingon dialect that was originated by James Doohan, and then later expanded into a full language by linguist Mark Okrand. This is generally accepted as the canon language for these ridged headed aliens.
Ronald D. Moore, who is the 'Klingon guy' in Star Trek - he wrote many of the best Klingon episodes - has said that one shouldn't hold up a dictionary while listening to the Klingon language being spoken in his episodes. He says that whether or not they use the official language is up to the writer, as jotting it down word for word is quite cumbersome.
This may have been somewhat dismaying for Okrand to hear - developing a language is hardly the easiest job in the world!