A True Sabbat is a vampire who has undergone the Creation Rites. In opposition to the False Sabbat, these are considered worthy Cainites who have proven themselves in combat or intrigue against their rivals.
The typical attitude is that being a True Sabbat is a matter of importance and distinction - you don't want just anybody coming in and claiming all the rights and privileges of Sabbat without having proven themselves first. Also, given the pack structure of the sect, many members think of themselves as a collection of gangs or neo-feudal warbands, complete with initiation rites and other ways of making themselves feel special.
- Caine's Chosen: The Black Hand, p. 38 (ritus and oath of initiation)