Parties having their residence or principal place of business in a contracting state are not obliged to be represented by a professional representative in proceedings before the EPO. They may, irrespective of whether they are legal or natural persons, be represented by an employee, who need not be a professional representative but who must be authorised. However, where such parties wish to be represented professionally before the EPO, such representation may only be by a professional representative. The parties themselves may also act directly before the EPO, even if they are represented by an employee or a professional representative. When conflicting instructions are received from the party and his representative, each should be advised of the other's action.