A relative pronoun is a °relativizer that can carry a °flag or has distinct forms for the roles °A and °P.
Relativizers sometimes show gender or number distinctions reflecting the gender/number of the head noun, as in Standard Arabic, but do not carry a flag or distinguish syntactic roles. Such relativizers are not regarded as relative pronouns. (Cf. Comrie & Kuteva (2005: 494): "Note that the mere presence of a pronoun that is restricted to relative clauses, and is thus in some intuitive sense a relative pronoun, is not sufficient to define an instance of the pronoun strategy (Comrie 1998: 61-62). Such a relative pronoun can be case-marked, for instance, not to indicate its role in the relative clause, but rather to agree in case with the head noun in the main clause.")
relative pronoun (CXN) = a pronoun form that is unique to the relative clause construction, and is found in the externally headed relative clause construction using the relative pronoun strategy. Example: in He stole the emerald [which he gave to his wife], which is the relative pronoun. (Section 19.2.2)