[Subsentient]

Both, though mostly documentation. To me, a standard is the documentation. The fact I have to read rustc source to find syntax is frankly an abomination. A standard defines syntax and grammar in ways that a html reference page never does. It doesn't matter as much for "fluffy" languages like Python or Lua, but it's very important for a systems language.

I also want standardization to make writing alternative conforming compilers easier. I strongly dislike the attitude of some Rust maintainers, and a standard is a useful tool to forcibly remove some level of control from their hands.