zpool(1M) and zfs(1M) need to better describe allowed characters in dataset names
currently, zpool(1M) has the following:
The pool name must begin with a letter, and can only contain alphanumeric characters as well as underscore ("_"), dash ("-"), and period (".").
and zfs(1M) doesn't say anything about dataset names at all.
The problem with the description is that set of characters that can be described as
alphanumeric depends on the locale, while in reality we only allow
[a-zA-Z], so we should either say
ASCII alphanumeric characters, or