It is the raw packets "vis_flags" data; bitwise and other assorted values I think LE and crew figured out in the beginning. Might help us in tweaking some of our spawn data.
vis flags:
2 = show icon
4 = targetable
16 = show name
32 = show level/border
activity_status:
4 - linkdead
8 - camping
16 - LFG
32 - LFW
2048 - mentoring
4096 - displays shield
8192 - immunity gained
16384 - immunity remaining
attackable_status
1 - no_hp_bar
4 - not attackable
npc_con
-4 = scowls
-3 = threatening
-2 = dubiously
-1 = apprehensively
0 = indifferent
1 = amiably
2 = kindly
3 = warmly
4 = ally
quest_flag
1 = new quest
2 = update and new quest
3 = update