OMM AL-KET_B, title of an anonymous Persian book associated with certain early Shi_ite _ol_t (extremist) groups of southern Iraq. The origins of this syncretic text, produced initially in Arabic, are shrouded in mystery. Subsequently, this work found its way into the manuscript collections of the Nez_ri Isma_ilis of Bada___n (an area now divided by the Oxus River between Tajikistan and Afghanistan) and adjacent areas, such as Hunza and Chitral, all situated in Central Asia. The Central Asian Nez_ris, thus, regard the Omm al-ket_b not only as an Isma_ili text but also as one of their most sacred and secret works, although it does not contain any known Isma_ili doctrines.