This article studies the use of nominal terms and pronouns as a means to refer to a third party, as well as to the writer him/herself and the addressee in written interaction. The purpose is to discuss the concepts of person reference and social deixis by looking at how the interactants' social identities and interpersonal relationships are encoded in the use of referential terms in Late Modern English letters and journals. The results show that the term friend may be used when the writer has something to gain from it: an actual favour, a reciprocal act of solidarity, or an access to the addressee's/referent's in-group. In general, shifting between in-group/out-group membership appears to be a common function for the use of friend. The use of addressee-and self-oriented reference is in turn determined by the social and contextual aspects of appearance, attitude, and authority.