When annotating a speech signal using an autosegmental-metrical model of intonation, transcribers associate portions of the F 0 contour with labels from a finite inventory of tonal categories. In the models we are concerned with here, these categories have the status of phonological units (phonological form), bridging the intrinsic variability of the speech signal (substance) with the intrinsic fuzziness of post-lexical function (meaning). This, together with the relatively small size of the label inventory, precludes a one-to-one relationship between form and substance, and/or between form and function. A Neapolitan Italian corpus of read speech is used to investigate the distributional properties of two pitch accents that have been studied extensively with respect to substance (the alignment of F 0 peaks) and meaning (sentence modality). Although there is a general consensus that peaks in this variety are aligned earlier in declaratives than in interrogatives, evidence is provided of contexts in which the converse is true, i.e., in which interrogative peaks are even earlier than their declarative counterparts. In this respect, interrogatives have a richer internal structure than declaratives. We argue that differences in how variably a prosodic category is encoded can be dealt with in an intonation transcription system, as long as this system relates phonological form (the choice of pitch accent in this case) both to phonetic substance and to meaning in a transparent way.