Recoverability in Slovene Relative Clauses

In Slovene restrictive relative clauses, exactly one element can and must be overtly expressed in the CP domain. An investigation of standard Slovene and in its dialects shows that a relative clause is introduced either by the pronoun kateri, or by ki, a complementizer. Another property co-varies with this choice: when the relative clause is introduced by the complementizer, the head noun is obligatorily resumed by a clitic pronoun. I suggest that this resumption is the result of the spell-out choice governed by restrictions on the CP domain and recoverability requirements.