Lisaan ud-Da'wat or Lisaan o Da'wat il Bohra or Lisan ud-Dawat (Arabic: لسان الدعوة, lit. 'language of the Da'wat', da'wat ni zabaan; abbreviated LDB) is the language of the Dawoodi Bohras and Alavi Bohras, two Isma'ili Shi'a Muslim communities primarily in Gujarat, following the Taiyebi doctrines and theology. The language is based on a Neo-Indo-Aryan language Gujarati, but incorporates a heavy amount of Arabic, Urdu, and Persian vocabulary and is written in the Arabic script naskh style. Originally a ritual language, since the period of the missionaries-دعاۃ in Ahmedabad around 1005 AH/1597 AD it has also been propagated as the vernacular language for members of the Bohra communities, but the version used by their religious leader-Saiyedna and his assembly members or clergy still differs