The Shari Tcha'kla was a group of 30 Vulcans whose raison d'être was to monitor members of the Twelve Families to ensure that they hewed to a Surakian ideal of thought and behavior. Those who did not were deemed v'tosh ka'tur -- Vulcans who rejected the teachings of Surak, and were without logic. Such individuals were banished from Vulcan society. They called themselves the "Guardians of Vulcan", but while their primary task was being the guardians of the Vulcan way, they also were the physical guardians of members of the Twelve Families.