If a site adds a domain in create account, then in the new create account form a "Your domain" <select> choice appears between Password and Retype password. See https://wikitech.wikimedia.org/wiki/Special:UserLogin/signup?useNew=1
- wikitech has custom CSS to hide the domain field, but the new form lost the ID for it. Easy fix coming.
- the new login form uses the wrong message key for "Your domain". You don't see this glitch on wikitech because its CSS to hide the domain field works for login.
It feels wrong to have a field between password and retype password, but if your password is associated with a domain I guess it makes sense.