Not Named vs Default and related matters

I yesterday saw that one of our team captains had entered two boards using the player name "Default(0000)". However, what he was meaning by this was simply that he didn't know the names of the relevant players on the opposing side. Now I personally think it's a captain's responsibility to make sure he has a record of the players names, but can see that this will occasionally happen. However, it leads to two or three related thoughts:

(1) It would be useful to have report on defaults (similar to "New Player" reports)
(2) To my mind it would have been more natural for the captain to enter "Not Named", but that can only be used in combination with "0(def)-1" and "1-0(def)" results. Strangely, the system accepts the player "Default" with a wider set of results.
(3) If we allow "Not Named / Unknown" to be used on non-defaults, a "Not Named" report on those games would also be useful.

Perhaps the easiest solution is to only allow "not named" on defaults. Perhaps a player of "Default" is not necessary. Maybe "Not In List" would have been better than "New Player". Maybe there is a case for generalising the New Player matches report to cover other things.