Good point. There isn't even a good website for RSS. RSS.com is a podcasting service. RSS.org is the website of some guy who has these initials. The most official source is the wikipedia page, which obviously is a just neutral explanation, not trying to advertise it. There's a site called You Need Feeds[1], which is trying to advertise it, but it doesn't look official and doesn't show up on the first page when you google RSS (which according to keyword planner 10K to 100K people do in the US alone).

[1]: https://www.youneedfeeds.com/