The term co bac is an interpersonal reference meaning “aunts and uncles” (…). These “aunts and uncles” are dead, but not really dead in the sense of being settled in the am (the world of the dead); they are not alive, but they still have not left the world of the living. They are neither really there in the world of the dead (am) nor here in this world (duong), and, at once, are in both. The idea of “wandering” in terms of wandering spirits points to the imagined situation that these spirits are obliged to move between the periphery of this world and the fringe of another world.
Heonik Kwon, Ghosts of War in Vietnam