Reflectors can contain address for both local and remote users.
In the special case of automatically populated class reflectors ur probably isn't needed much beyond their creation because these default to being updated daily from the class list database. However, if the owner wants to include more non-registered students on the reflector such as teaching assistants, they'll need to use ur to edit an exception list for the reflector which gets merged in when the update is done from the classlist. In the case of students in classes who are on commercial internet provid- ers, the exception list editing feature can be used. Otherwise one has to add them to the reflector's exception list, another professor has to add them to theirs, and so forth. The full name field in the reflector as created is not required in the reflector or exception list but is there to help the instructors associate login names with real names.