I just filled in an issue over in Node.js about including 'gender identity and expression' into their Code of Conduct: nodejs/inclusivity#82. I know that Node effectively adopted the Rust CoC so I thought I should come over here and suggest the same thing, as I am very interested in learning Rust, too!
I am proposing that we include 'gender identity and expression' in the Code of Conduct used for all of Rust. I've managed to include this in the Codes of Conducts for several event and online communities of a smaller nature, so I'm hopeful that people seem to be receptive to the idea.
Solely referring to 'gender' does not recognise the non-binary or agender folk. (As often, 'gender' is widely regarded as the popular idea of man/woman). Gender identity feels like a clearer and more inclusive term.
I realise the CoC says 'similar personal characteristic', but it feels like it'd be good to have things explicitly said rather than assumed. The Contributor Covenant has a lot of really useful things in it too (like age, technology choices, lack of religion), which we could consider co-opting things from.
I hope I explained myself well, and I'm happy to answer any questions.
Thanks so much for reading!