So the Advanced Loot window was added at sometime during my absence, and I admit it's perplexing. I watched a couple of YouTube videos and feel like I understand it pretty well, but this weekend, I ran into a strange situation. I was in a two man group and one of the people died and during the time they were running back to the zone (no rez available), the other person killed a few creatures and put more loot in the window. When the other person returned, all the loot was marked with a big red lock and even the main looter couldn't give it to that person without that person first clicking on the corpse. Problem is, he couldn't click on the corpse. The corpse in question was untargetable by the person who had been out of the zone. No left-click, no right-click. Were we doing something wrong? Or is this not working like the in-game message said? *edit* I should mention, the item was a no-drop item that he needed for a quest, otherwise I could have looted it and given it to him.
Sometimes targeting corpses is wonky. Have 1 person in the group target it, and then /assist. Or /tar mob name can work. There is also a key bind for target next corpse.
The person coming back into the zone will need to make sure they don't have /hidecorpse always activated. They can issue the command /hidecor none In addition to cycling through corpses, it's possible to target a corpse directly. However, it can become difficult if there are multiple corpses with the same name. For instance, if the loot is on "a bone golem," the person can use the command /tar a_bone (the underscore is needed in place of the space in the npc name) After the corpse is targeted, typing /loot should unlock the items in the advanced loot window.
Also, if the main looter dies and is out of the zone then the group leader or person who has been in the zone the longest will be the defacto looter until the main looter returns. Only those who are outside the zone at the time of the kill will need to right click or /loot the corpse to unlock it to them.