1. Except where use of electronic means is mandatory pursuant to Article 33(2) and Article 34, Member States or contracting authorities and contracting entities may choose one or more of the following means of communication for all communication and information exchange:

(a) electronic means;

(b) post or fax;

(c) oral communication, including telephone, in respect of communications other than the essential elements of a concession award procedure, and provided that the content of the oral communication is documented to a sufficient degree on a durable medium;

(d) hand delivery certified by an acknowledgement of receipt.

Member States may make mandatory the use of electronic means of communication for concessions, going beyond the obligations established in Article 33(2) and Article 34.