T. Dorandi, who has previously proposed to read the book number included in the end-title of P.Herc. 1669 (Philodemus’ On Rhetoric) as a numerical ϝ-shaped digamma (= 6), has now advanced the same reading in the subscriptio of P.Oxy. 1176 (Satyrus, Lives book 6), where the editor princeps and all subsequent editors had unanimously read a stigma before. In this article, I argue not only that both readings are palaeographically untenable, but also that they historically contradict the graphic and functional evolution of digamma within the Greek alphabet. In particular, in both Graeco-Egyptian and Herculaneum papyri, ϝ-shaped digamma is always attested as a merely phonetic element (/w/ or waw) – never as a numeral symbol – whereas stigma, which represents the historical evolution of a variant of Archaic and Classical digamma, is the only form used as a numerical sign (= 6).