The Typikon, or Typicon (Greek: Τυπικόν, (typikon), lit. "following the orer"; Slavonic: ѹставъ, (ustav)) is a liturgical book which contains instructions about the order of the various Eastern Orthodox Christian church services and ceremonies, in the form of a perpetual calendar. Those Eastern Catholic Churches that use the Byzantine rite also follow largely the same typica as their Orthodox counterparts, with minor variations.