Artikel 3

1. The Contracting States may entrust the national exchange service or, where no such national exchange service exists, the central exchange authority or authorities with the following functions in connexion with the development and co-ordination of the exchange of publications among bodies and institutions referred to in Article I of the present Convention:
(a) facilitating the international exchange of publications, in particular by transmitting, when appropriate, the material to be exchanged;
(b) supplying advice and information on exchange possibilities for bodies and institutions at home and abroad;
(c) encouraging, when appropriate, the exchange of duplicate material.
2. However, when it is deemed undesirable to centralize in the national exchange service or in central authorities the development and co-ordination of exchanges among bodies and institutions referred to in Article 1 of the present Convention, any or all of the functions enumerated in paragraph 1 of the present article may be entrusted to other authority or authorities.