This article reports the results of a study based on a corpus of simple (i.e. only written) and complex (both written and oral) shortenings, that is, initialisms (a category comprising acronyms, e.g. laser, and alphabetisms, e.g. BBC), as well as clippings (lab), blends (motel), and abbreviations (Mr). The study intends to confirm the validity of the tools provided by the revised version of prototype theory for a systematic account of these metalinguistic categories, which are often neglected in lexical morphology. A set of defining parameters and possible values was devised and applied to the items of the corpus. As a result, these items were distributed along a continuum of central, peripheral, and borderline cases of all the categories considered. The body of the article is an in-depth account of the centre–periphery structure of the superordinate category of initialisms, with particular attention being paid to the fuzzy boundaries featuring clippings and blends. In the last section, shortenings are categorized and represented by means of a radial polycentric network of the type devised in Lakoff (1987).