A mage's spells come with a mystical stamp of his personality: his aura. Mages with the Occultation Merit, however, can dampen his own resonance and Nimbus through an act of his own will. This effect clears the mage of every means to detect him, making even mundane means like photography unable to pin him down. Occulted mages tend to live on the fringes of mundane reality, as though they are an anomaly or aberration. Sleepers have trouble keeping track of their identities and activities. Records regarding an arcane mage tend to get lost, and the authorities are challenged to investigate his activities. Since most Sleepers find it hard to gather information about the mage, they won't know many details about him.
If the mage ever becomes well known to the public (such as getting caught on camera and being shown on television night after night), he loses his Occultation until the public at large forgets him (which could take many years, depending on how famous or notorious the mage became). Likewise, if he maintains a public persona at all among Sleepers, even to the degree of having many Sleeper friends, he cannot maintain his Occultation. The mage must constantly cultivate this Merit, working to remain away from the attention of Sleeper society. It does not affect his standing in Awakened society.
Rumors tell that Archmages have such a strong affinity to Occultation that even Awakened mages are likely to forget them. The Blank Badges, a Legacy from the Free Council, cultivates this Merit with their Attainments.