Mainly I am looking for a way to tell users attempting to create accounts to "See Ms. Nebbercracker in room B344 if you need an account."
As I have turned off create account permissions, there will be no create account link (once https://bugzilla.wikimedia.org/show_bug.cgi?id=63456 is fixed).
So I need to a way to put that message on the login page, like I do for desktop.