Transmission formulas disclose the alleged way a report was acquired. The eight modes of taḥammul differ in what they establish and therefore cannot all be assigned identical evidentiary value.
Direct audition and reading to a teacher involve an actual teaching session; permission, handover, writing, information, bequest, and discovery may involve authorization, possession, attribution, or mere access to a written text. Where hearing did not occur, its explicit formula should not be claimed.
The continuity of ʿanʿanah requires separate attention to contemporaneity, proof of meeting, and tadlīs. Broad or unidentified authorizations require further caution because classical scholars differed over their status.
The next discussion develops the identification of transmitters whose names are identical, a distinct problem addressed under al-muttafiq wa-l-muftariq.