there’s a specific wikipedia article for “star trek canon” and in it i read, “Roddenberry considered elements of Star Trek V and Star Trek VI to be apocryphal,” so honestly if star trek canon ends after The One With the Whales for gene roddenberry himself then goddamnit that’s where star trek canon ends for me too
Read the entire article.
What GR considered canon and non-canon was anything but specific.
“People who worked with Roddenberry remember that he used to handle canon not on a series-by-series basis nor an episode-by-episode basis, but point by point. If he changed his mind on something, or if a fact in one episode contradicted what he considered to be a more important fact in another episode, he had no problem declaring that specific point non-canon.”
That’s no way to define anything, whether it’s the internal structure of a franchise, the meaning of a word or the ingredients in a recipe.
When @dduane and I were involved with the ST novels, information
from Pocket Books
to writers indicated that all characters, incidents and references which had appeared on screen
(including IIRC the animated series)
were regarded as canonical.
The novels themselves (also comics, game supplements, model kits, action figures etc.) were not canonical, which gave freedom of “internal reference” - the Klingon supplement for the Star Trek RPG was based heavily on John M. Ford’s novel “The Final Reflection”. Ford also wrote that splendid eccentricity “How Much For Just The Planet”, which put comic-opera into space opera…
About 1988-89 the rules were tightened, the animated series was decanonised and various other regulations were enforced. About ten years later DD’s take on the Romulans - “My Enemy, My Ally” and “The Romulan Way” - were granted what fanfic would now call Officially-Sanctioned AU Status as “Rihannsu” to allow the writing and publication of sequels.
Since Romulus and indeed Vulcan no longer exist in Post-Reboot Trek, I suppose that makes the Rihannsu a sort of loose canon… (hides)