Question about notations and domains

[Khelben Blackstaff]

Greetings.

I am sorry if this is already answered but i could not find anything
relevant in the archive.

Quick introduction: I got a new smart card and reader so i thought to
create a temporary test key and document on my blog all the steps i
did over the years. In the next post i want to describe the policy urls
and notations i use.

If i have understood the standard correctly, notations should have
the form tag at my.domain.tld using a domain i own because my meaning
for "tag" might be different than someone else's. Is this correct ?

Some users do not own a domain but have a github account. For some time
now, github supports creating a repository containing html files and
naming it username.github.io. Then http://username.github.io renders all
the files in that repository as a normal webpage.

I wouldn't want to encourage bad practice so i worry if i should
mention this functionality or not.
(for example issuer-fpr at username.github.io=%g)
The user controls the content of the repository but he does not "own"
the domain (neither it is a real domain). Also sending e-mail to the
notation name will not work (though this functionality is optional).

Are notations with such a "domain" a valid case or are considered bad
practice and should not be used ?

Another question i have is about the pgpmime notation. I see many
people using it verbatim "preferred-email-encoding at pgp.com=pgpmime".
Shouldn't @pgp.com be changed to the domain of each user ?

Thank you for your time.