Posted by Forbin:
Like, "when did the unspoken rule that there can be no occupied hullspace between two warp nacelles got thrown away?"
(short answer: "The Wounded" with the first appearence of the Nebula class)
I'm not sure there's a quick-and-easy answer to the question of "Roddenberry's Rules" that won't be a debate in and of itself, though. "They were a fairly groundless attempt to discredit FJ after Roddenberry had a falling-out with him" is accurate, but is likely to start more arguments than it ends, eh?
But... That does give me an idea...
<Dashes off to make some edits>