this paper, is not a language-specific one, in spite of the fact that most of the languages have their own repository for marking the role of the addressee in communicative utterances. In our opinion this linguistic phenomenon needs its adequate treatment because of two main reasons: 1. The vocative is supposed to be present on two levels: syntax and pragmatics. Therefore it needs more elaborate interpretation on the interface side, which, in HPSG, is more developed for morphology /syntax and syntax/semantics than syntax/pragmatics; 2. It will be useful for HPSG-oriented implementations, especially treebanks and dialogue systems. The paper is structured as follows: in the next section the status of the vocative in Bulgarian is discussed. In section 3 we propose our ideas on a unified treatment of vocatives. In section 4 the HPSG model is given. Section 5 outlines the conclusions and future work. 2 The Status of the Vocative in Bulgarian Vocatives are assumed to be restricted to the second person usage only. Usually they subsume the following two subtypes: calls (hey you) and addresses (Madam) [Levinson 1987, p. 71]. Bulgarian vocative role is usually treated within the opposition: vocative form (a remnant of the case paradigm) vs. base nominative form, i.e. with respect to the presence or loss of the special vocative inflections. Hence, The work reported here is done within the BulTreeBank project. The project is funded by the Volkswagen Stiftung, Federal Republic of Germany under the Programme "Cooperation with Natural and Engineering Scientists in Central and Eastern Europe" contract I/76 887. The authors wish to thank the Seminar fur Sprachwissenschaft of the Eberhard-Karls-Universitat, Tubingen, for hosting the writing of this paper, and the Internationales Zentr...