When you add a referee, you also have the option to add a "Dummy Referee". A dummy referee has only a single identifying (first) name. In lists of referees, they are listed with their identifying name followed by the last name "Dummy". For example, if the supplied identifying name is "Metro League", they will appear in the referee list as "Metro League Dummy".
As the word implies, dummy referees are not real people - as such, they have no log in credentials and adding one does not add an actual user to our system. Instead, they are intended as "placeholders" for referees who, for instance, are assigned by someone outside our system. Typically the identifting name supplied might be the name of the league or organization that is actually responsible for assigning them.
Dummy referees do have optional email addresses. If an email address is supplied for a dummy referee, that address will receive emails if, for instance, a game is rescheduled that the dummy referee has been assigned to. So often the email address will actually be the email address of someone who has responsibility for assigning a real referee to a position the dummy is assigned to.
Of course, because of the intended use of these dummy referees, we allow them to be assigned to concurrent and/or overlapping assignments with no warnings generated. Thus a single dummy referee can be used to represent many actual referees.