One noteworthy feature of Philadelphia English is widespread variable /l/-vocalisation, even in intervocalic contexts. This study constitutes an attempt to circumscribe the contexts in which /l/-vocalisation is possible in Philadelphia English, with reference to the other commonly attested allophones; light and dark /l/. Ultimately, it appears that /l/ vocalisation is limited to phrase-, word-, or stem-final position, or to post-tonic position. We do not observe stem-medial, non-post-tonic /l/ vocalisation, such as in the word ‘gelato’. These environments are a subset of those in which we observe /l/ darkening, which in turn are a subset of the contexts in which light /l/ is found. This supports the view that the allophones of /l/ form a continuum, from light to dark to vocalised. Moreover, when we limit our data to just those contexts in which /l/ vocalisation is possible, a clear diachronic picture of the increasing frequency of /l/ vocalisation emerges even with a small pool of speakers.