In this paper, the dichotomy of restrictive and appositive relative clauses is argued to be a consequence of the semantic interpretation of the relative pronoun, which is analyzed as an operator in case of restrictives and as an anaphoric pronoun in case of appositives. Empirical evidence supporting the anaphoric account of the relative pronoun comes from Russian. The paper shows that the range of interpretations of the pronoun kotoryj which in appositives is identical to those of regular 3rd person anaphoric pronouns.