I thought that once we are in game, and if the corps are big enough, you may not know that the guy/gal walking behind you isnt a stalker, just a fellow corp-mate going to the same place as you.
This could be fixed by having little corp mini logo's shown in the characters tag. Maybe to a max of 5 logos.
(Having corp mini logo's on part of the characters body would also be good - maybe on the shoulder/upper arms? This could be all the logo's as there are more rooms on arms than in tags.)
Assuming there is also a friend or foe system in DU maybe also a little green/grey/red circle in the tag showing if friend/neutral/enemy.
(Though technically, since there are multiple corps, you may have the situation that someone is both friend and foe )
This way you can see friends from foes - most of the times