Veil

A veil is a magical form of concealment which renders the affected either invisible or otherwise unnoticed by most of the magically unaware. Veils can range from simple feelings of aversion to looking in a direction, to a lack of conscious recognition of someone's presence, to a complete state of invisibility and denial of the existence of the physical space in which the veil stands.

Veils can be seen through with the Wizard's Sight and perhaps some varieties of sentient magical creatures.