Two types of pronominal elements may appear in Catalan nominal constructions: the possessive pronoun and the strong pronoun. These elements differ in distribution, syntactic behavior and denotative properties. This paper proposes that the alternation between possessive and strong pronouns in nominals is parallel to the alternation betweenpro and strong pronouns in clausal structures. The possessive in nominals and in clauses instantiate the Avoid Pronoun Principle, whose application affects feature specification in the referential grid of pronominal elements, and not the phonological content of pronouns, as has traditionally been assumed.