10 Greatest Star Trek In-Jokes
6. Smoothing Things Over
The Klingons have gone through many, many changes since their original appearance in Errand of Mercy. At first conceived by writer Gene L. Coon as the Soviet half of his Cold War allegory, Kor actor John Colicos reportedly looked more to the likes of Genghis Khan for inspiration for the character, leading to some very problematic make-up choices.
They certainly didn't have the budget in TOS that they did by the time the Klingons reared their ridges in The Motion Picture. The make-up and general look was further designed and re-designed in the films (with Klingons) that followed, and then again… and again in The Next Generation and Deep Space Nine with no explanation given. As Michael Dorn knowingly commented in an interview with Cinefantastique, Vol 32, no 4-5, "I guess they never thought they'd have to deal with it [on screen] at some point".
Therein lies the in-joke when DS9 decided to tackle the changes in Klingon appearance head-on (ish) in Trials and Tribble-ations. If you can't put ridges on it, hang a lantern on it instead. Worf's laconic "It is a long story… We do not discuss it with outsiders" was about all the answer we needed, and were going to get, until the Enterprise explanation, which everybody loved and there have been no problems since!
*cough*