In large part ETP follows the standard system of transcribing Etruscan inscriptions, for example, that employed by Rix et al. for Etruskische Texte. We depart from this system for the representation of sibilants. We indicate the dental/alveolar sibilant by means of the letter s, regardless of its form in Etruscan orthography. We indicate the palatal sibilant by the letter σ, regardless of its form in Etruscan orthography. Our system for transcribing sibilants is phonological, unlike the systems generally employed in other texts on Etruscan.

The retrograde epsilon found in inscriptions from Cortona and environs is transcribed by means of the letter e with a diacritic placed over the letter, thus ê. This sound represented by this letter appears to have been phonologically distinct from the sound represented by the 'regular' epsilon, that is to say, by the epsilon written facing the direction of writing.