Within the corpus of manuscripts attributed to Sultanate India (thirteenth to sixteenth centuries), one group of Korans stands out. These Korans, which are in the Bihari script, follow precise and recurrent rules. They are defined by the use of Bihari calligraphy, a writing style specific to the Indian subcontinent, as well as by a common ornamentation and a particular page layout that reveals a complex hermeneutical system. This system is made up of different categories of texts related to the Koran, among which are repeated references to the canonical readings, or qira'āt. Several manuscripts also contain a book of divination (fālnāma) appended at the end. The oldest specimens are among the earliest known manuscripts for India, even though their production extended into the nineteenth century, which raises numerous questions about the milieu in which they may have come into existence and the uses for which they may have been intended.