neutral hostile and neutral passive.. Those would probably be 13 and 14.. Then 15 and 16 would have to be something like rescued or other types of units...
Observers just mean that you take like a 4 player map.. add 8 players onto the end of it that allows it to be watched.
0-11 are the normal players
12 is nuetral passive
13 is nuetral hostile
14 is rescueble
15,16 have been found out, I knew it before but I don't right now. StonedStoopid would.