I am not Spock wrote:
As good as Eye of the Needle is, its not really 'about' the Romulans, per se, is it? But I suppose 'Trouble with Tribbles' wasn't really about the Klingons, and it was on the Klingon collective DVD.
The Trouble With Tribbles, Trials and Tribble-Ations, and Broken Bow aren't really about Klingons, and they all made it to the Klingon set.
Technically speaking, Year Of Hell isn't really about time travel. Yes, a device is ued which alters the timeline, but not actual time travel happens in the episode. Yet it is still on the set titled Time Travel.