The Dēnkard or Dēnkart (Middle Persian: 𐭣𐭩𐭭𐭪𐭠𐭫𐭲 "Acts of Religion") is a 10th-century compendium of Zoroastrian beliefs and customs during the time. The Denkard is to a great extent considered an "Encyclopedia of Mazdaism" and is a valuable source of information on the religion especially during its Middle Persian iteration. The Denkard is not considered a sacred text by a majority of Zoroastrians, but is still considered worthy of study. Source: Wikipedia (en)