KWFA PROSWPA

Aristophanes, Clouds, Wasps, Peace. Edited and Translated by Jeffrey Henderson (Cambridge: Harvard University Press, 1998 = Loeb Classical Library, 488), p. 426 (in the Dramatis Personae for Peace):

kwfa proswpa

This a mistake for ΚΩΦΑ ΠΡΟΣΩΠΑ (i.e. non-speaking characters). See pp. 8 and 220. And yes, I know what caused the mistake—something like this:

A friend once called me Λοεβομάστιξ (Loebomastix, i.e. castigator of the Loeb Classical Library; cf. Ὁμηρομάστιξ = Homeromastix).