Phonological regularities in a given language can be described as a set of formal rules applied to logical expressions (e.g. the value of a distinctive feature) or alternatively as distributional properties emerging from the phonetic substance. An indirect way to assess how phonology is represented in a speaker's mind consists in testing how phonological regularities are transferred to non-words. This is this objective of this study, focusing on Coratino, a dialect from southern Italy spoken in the Apulia region. In Coratino, a complex process of vowel reduction operates, transforming the /i e ɛ u o ɔ a/ system for stressed vowels into a system with a smaller number of vowels for unstressed configurations, characterized by four major properties: (1) all wordinitial vowels are maintained, even unstressed; (2) /a/ is never reduced, even unstressed; (3) unstressed vowels /i e ɛ u o ɔ/ are protected against reduction when they are adjacent to a consonant that shares articulation (labiality and velarity for /u o ɔ/ and palatality for /i e ɛ/); (4) when they are reduced, high vowels are reduced to /ɨ/ and mid vowels to /ə/. A production experiment was carried out on 19 speakers of Coratino to test whether these properties were displayed with non-words. The production data display a complex pattern which seems to imply both explicit/formal rules and distributional properties transferred statistically to non-words. Furthermore, the speakers appear to vary considerably in how they perform this task. Altogether, this suggests that both formal rules and distributional principles contribute to the encoding of Coratino phonology in the speaker's mind.