An account is needed to list a repository. Nothing else here requires one.
3 to 24 characters: letters, numbers, hyphens, underscores and full stops. This is public, and it is shown on everything you list.
Used to confirm your account and to reach you about a listing. Never shown publicly.
Either works. The link goes to the address on the account.
At least 10 characters. Length is what matters, so there are no symbol rules.
Plugins