I am surprised that I even have to ask this question, but here I am.
If I were talking about some obscure board game only ten people in the world know, it would be safe to assume the official regulations would not be easy to find online; but backgammon is rather famous as a board game, some even claiming it is the oldest board game in existence.
And yet, I cannot find an official reference for its rules anywhere. The most natural place to check would be the website of the World Backgammon Federation—but I swear to you, and you can check for yourself, that the ruleset they provide (link, and relative PDF) only deals with tournament stuff such as what to do when players are late to a game and things like that; even the section that is literally titled ‘The game’ only covers stuff such as changing a bad dice or dealing with a player who accidentally makes an illegal move. But there is nothing on the actual mechanics of the game.
You would think about going to Wikipedia, since there must be a Rules section in the relevant Backgammon page. And there is. But the best source for them that is provided in the page is this website here. Backgammon Galore—an amateurish website that looks like it comes straight out of the 90s, that is managed by god only knows who and that does not seem to be officially affiliated with any federation whatsoever. Needless to say, any other resource on the rules of backgammon eventually leads back to this page or employs pictures or content taken from this page.
My question is: how is this possible? Does a game as famous (and old) as backgammon really not have an official ruleset anywhere, or have I just looked in the wrong place all along?