If room creation is restricted via the Room Creation Restrictions dialog in the admin console and someone without permission attempts to create a room they are returned a 401 error:
I was curious as to what this error meant so I looked it up in the JEP which states:
401 Error Presence Entering a room Inform user that a password is required
I think a more apt error might be:
405 Error Presence Entering a room Inform user that room creation is restricted
As always, thanks.