Good to know - neither the parent nor the article mention this. h2c seems to have limited support by tooling (e.g. browsers, curl), which is a bit discouraging.
It does. Just use `--http2` or `--http2-prior-knowledge`, curl deduce the clear or not clear by `http` or `https` URL protocol prefix (clear the default).
I said limited support and gave curl as an example because curl --http2 sends a HTTP/1.1 upgrade request first so fails in a purely HTTP/2 environment.
Thanks for bringing up --http2-prior-knowledge as a solution!
EDIT: Based on the HTTP/2 FAQ, pure h2c is not allowed in the standard as it requires you to implement some HTTP/1.1 upgrade functionality: https://http2.github.io/faq/#can-i-implement-http2-without-i...