• You can bring up a specific book with `rustup doc --book`, `rustup doc --embedded-book`, `rustup doc --nomicon` etc... (use `rustup doc -h` to see the list). Yes works offline too.

• It should obvious because it's right there, but I somehow totally missed it, and so did the few people I mentioneded it to since: There is either a search box or a symbol on every single `rustup doc` pages. It works really well and typically allow to find what you're looking for quickly. And yes, it too works offline!