This ship was intended to be a mirror universe counterpart to my U.S.S. Anubis, which has the same registry number.
However, the concept for my U.S.S. Anubis was that she was an experimental ship, commissioned specifically to test a refit design, justifying the high registry number considering the class of ship.
I just didn't bother to change the registry number when I did the I.S.S. Anubis.