Whenever I throw anything, it becomes engraved with "#t". Anything with this inscription seems to be picked up automatically, but simply dropping such an item removes the inscription.
As I write this it actually seems like it could be intentional, but maybe there's a more elegant marker for thrown items to be autograbbed, and maybe the tag could be removed when the item is picked up. But doesn't picking up an item take a turn? That could be dangerous. I'm just not sure about this feature, if it even is one...