In section "Defined fields" you write:
Non-ASCII characters are not supported.
I'm not sure if this applies only to keys or also to values? With the availability of IDN (https://unicode.org/faq/idn.html) in email addresses, supporting only US-ASCII values is too limited.
I'd suggest that we should allow UTF-8 for values, at least. It looks like we're standardizing on UTF-8 as our character encoding for directory documents in Proposal 285.
The state of prop-285 (open) was actually the reason why I did not put UTF-8 into the CIISS :)
Is prop-285 already implemented in tor?
In that case I'm happy to add UTF-8 as recommended.