Canon, AU's, when is it what for shows?

A comment about the Gilligan’s Island movies in antoher thread led me to consider the nature of fanon, etc., and open this general discussion thread. Warning - anyone who engages in discussion of slash of any sort will be subject to a bird of paradise either flying up their nose (the comical song) or perching on their head (I think that was the Johnny Carson line)

Now, Star Trek is one excample where I suspect the books become quasi-canon, if they’re good enough. Hikaru, for instance, was only ever listed as Mr. Sulu’s first name in the books, never on TOS. But, by Star Trek VI, I think it is, it is given as his first name, thus making it official canon. Were they admitting some books are canon, or what, do you think?

The sitcom “Full House,” in childrens’ books feturing the youngest twogirls, Stephanie and Michelle, probably take the most lgoical course, to me, as they make no bones about being an Alternate Universe, they state outright that certain things, from an office/den where the fourth bedroom is on the show to a different middle school, make it an AU. Since the series’ season 7 starts w/Stephanie going to a totally new Middle School, and she’s with her old friends int he books that started the same time, one can presume that they decided right away that the girls’ development made them less wild, etc., with less of Uncle Jesse’s wilder ways (especially when it came to Michelle) and that some school redistricting was also part of the TVU. There are other things which can be read about in my stories on

Anyway, the Gilligan’s Island movies seem to me to be worthy to be considered canon, except for those missing 12 years of course. If they are not, though what are they? Do you consider them AU? And if so, is anything ever canon after the original run of a TV show?

Mostly rmabling, I know, but I did want to make the points above and ask that question - how far does canon stretch? Or are there strict canon constructionists versus liberal ones, with the strict saying just the TV show, the liberals saying anythign that could be in the Tv Unvierse is?

Canon is when you like the story.

Alternate Universe is when you don’t.

There are only two Trek novels that are canon and both were written by Jeri Taylor about Janeway. Every other book, whether their history is later accepted or not, is in no way offical.

Similiarly, there is one episode of The Animated Series, Yesteryear, that is considered canon while the rest is disregarded.