Disciplina Arcani or Discipline of the Secret or Discipline of the Arcane, is a theological term used to describe the custom which prevailed in Early Christianity, whereby knowledge of the more intimate mysteries of the Christian religion was carefully kept from non-Christians and even from those who were undergoing instruction in the faith.[1]
http://en.wikipedia.org/wiki/Disciplina_arcani
Al-Jafr is a mystical Shia holy book[1][2] compiled, according to Shia belief, by Ali and inherited by him from Muhammad.[3][4][5] Al-Jafr is composed of two skin boxes in which were kept various books of the past Prophets and the books inherited from Muhammad, Ali and Fatimah to the Ahl al-Bayt, with each new Imam receiving them from his dying predecessor Imam, as well as the armour and weapons of Muhammad.[6][7]
Al-Jafr was one of the sources and origins of knowledge acquired by the 12 Imams and Imam Ja'far al-Sadiq took pride in having possession of al-Jafr, that comprised the hidden knowledge of Muhammad. The later Imams were accustomed to refer at times to the sacred and secret book of al-Jafr, which was left in their keeping by Ali and belief in the existence of al-Jafr with the Imams was firm, according to the Shia. [8][9][10][11][12][13]
The Imams also learned the science of Huruf (letters of the alphabet) from al-Jafr and used this science to derive facts and rulings from al-Jafr.[14][15]
Al-Jafr was handed down among the Imams until it is currently with Imam Muhammad al-Mahdi.[16][17][18][19]
Esoteric Shi'a Books not disclosed to lay believers:
`Umm al-Kitab, Kitab al-Azilla, Al-Jafr, Druze Book of Wisdom, Book of Fatimih (lost) [original name of Baha'u'llah's Hidden Words], al-Jamia
Influence of Mazdakism on Shi'a Revolutionary Movements?
The Batiniyya, Qarmatians and other later revolutionary currents of Islam may also be connected to Mazdakism and were often equated with it by contemporary authors.[16] Turkish scholar Abdülbaki Gölpinarli sees even the Kizilbash of the 16th century - a radical Shī‘a movement in Persia which helped the Safavid dynasty establish this branch of Islam as the dominant religion of Iran - as "spiritual descendants of the Khurramites" and, hence, of the Mazdakites.[17]"Mazdakist" eventually seems to have become a standard derogative label attached by pre-modern Persian and Arabic authors to any radical egalitarian movement in subsequent Iranian history.[18]
The author of the Dabestan-e Mazaheb, writing as late as the 17th century, claims to have met individual adherents of Mazdakism who practiced their religion secretly among the Muslims and preserved the Desnad, a book in Pahlavi containing the teachings of Mazdak.[19][20]