The fact that the subject clitic on has such a wide range of referential values has been studied extensively, in particular from a variationist perspective. Quantitative methods have been used (e.g. Laberge and Sankoff, 1980) to establish correlations between, on the one hand, on and its paradigmatic ‘equivalents’ tu and vous and, on the other, a number of linguistic, discoursal and social variables. Indeed, pragmatic factors figure increasingly prominently amongst investigated constraints on use and interpretation. It is the aim of this paper to explore, from a broadly qualitative, non-variationist perspective, and within the context of Brown and Levinson's ‘Politeness Theory’ (1978, 1987), how speakers can exploit the indeterminacy of pronominal reference and in particular that of the French indeterminate pronoun on in the interests of face protection.