This contribution reconsiders the question of indications of speakers in ancient Greek dialogue literature and their ‘invention’ by Theodoret of Cyrus by offering a systematic examination of the available (mostly papyrological) evidence. It discusses ancient conventions for marking changes of interlocutors in Greek literary dialogues and compares them with those present in dramatic works and in documentary and paraliterary texts such as reports of court proceedings, the Acta Alexandrinorum and Acta Martyrum, and reports of Church councils. It is hypothesized that the development of indications of speakers in Greek dialogue was influenced by documentary practices of the Imperial period and by paraliterary genres which imitated them.