Abjuration from Consensus is a Cetian phenomenon, usually proceeding from the Acolytes of Klaz, but it may be a decision reached by the entirety of the planet's Consensus all at once. These decision waves are known as Consensus Shocks, and while they happen rarely, they are powerful. Abjuration cuts an individual off from Consensus by the psychic force of every brain on the planet, and if the person in question is within 1 LS when it happens, the feeling of abjuration can leave psychic scars on the individual that lasts the rest of their life. If the decision is made while the person is absented from the planet, they might return to a cacophony of voices, followed by a sudden and eerie silence as their psychic signature is recognized and cut off. As they are not encountering Consensus Shock, the effect is less traumatizing, but no less disturbing.
Individuals who have been abjured often lose their family group titles and receive an abjuration name, which changes based on who they were, where they were born, and why they were abjured. For important families from the equator, such as the Del and Vas family lines, abjured individuals receive the new designation "Tu" as their family name. This designation makes it easy to distinguish that a person has been abjured on first glance in any paperwork, and the Cetian government has asked the Earth Republic to cooperate with the use of the designation for abjured refugees, to which the Republic has acceded. This designation becomes associated with a Cetian's biomarkers and psychic signature, in scans and all records, and it is very difficult to do any sort of business with Tau Ceti afterward or to remove the designation.
Very few individuals have ever returned to Consensus after abjuration, though it has happened. Typically, those who have been abjured leave the planet to work at an Acculturation Center, to try to redeem themselves and repair the rift. Letters, poems, and other communication is still permitted between the abjured and those in Consensus, but face-to-face communication is often unpleasant; most of Cetian language is psychic, and while they have a spoken language, it is difficult to understand another person while they are psychically cut off--a reason Cetians generally dislike robots and positronic cyborgs from other cultures, as these signals may be quieted (in a cyborg's case), twisted, or entirely absent, as with robots. Receiving cybernetics, especially positronics, is one of the most common reasons Cetians are abjured, but in the past, those who used their psychic powers to hurt others (as in the development of mind weapons), those who used empathetic ability to glory in the suffering of others, and those who murdered or raped in order to feel their victims' terror and pain (the sociopaths of Cetian society), were also deemed Hazards and abjured.
It is generally impossible to take part in Cetian society while abjured, even if one is not considered the guilty party. Cetian rites, language, and even sex require psychic linkage to be considered meaningful and complete. Once abjuration has taken place, the curtain between the abjured and the rest of their kind is so thick that they might as well be dead... which is the entire point.