The old Bajoran system of castes that fixed each person's occupation by family, abandoned during the Cardassian occupation and briefly revived by Akorem Laan when he was accepted as Emissary.
The d'jarras were the castes of traditional Bajoran society. A person's family determined their calling, whether artist, farmer, priest or soldier, and their rank relative to others. The system was set aside during the occupation, when every Bajoran became a fighter.
It returns in Accession in 2372. Akorem Laan, a revered poet lost for two centuries, emerges from the wormhole and is acclaimed as the true Emissary. Benjamin Sisko gladly gives up the title, but Akorem calls for the d'jarras to be restored. Kira Nerys, born into the artisan caste, tries to sculpt and prepares to resign her commission.
Caste discrimination would bar Bajor from the Federation, and a vedek is killed for refusing to yield to a higher caste. Sisko challenges Akorem, and the Prophets confirm that Sisko is the Emissary.