When a character who normally has a Halo is intentionally drawn without one, as opposed to a halo that is missing by mistake.
In Blue Archive, Halos are drawn to represent individuality and consciousness. The halo disappears when a character sleeps, goes Unconscious, or dies.
A common tell that the halo is intentionally missing is when other characters do have a halo. Don't use this tag if other characters are awake and don't have a halo: that's a sign of an Artistic Error.