Artikel 133

1. Subject to paragraph 2, no person shall be compelled to be represented by a professional representative in proceedings established by this Convention.
2. Natural or legal persons not having their residence or principal place of business in a Contracting State shall be represented by a professional representative and act through him in all proceedings established by this Convention, other than in filing a European patent application; the Implementing Regulations may permit other exceptions.
3. Natural or legal persons having their residence or principal place of business in a Contracting State may be represented in proceedings established by this Convention by an employee, who need not be a professional representative but who shall be authorised in accordance with the Implementing Regulations. The Implementing Regulations may provide whether and under what conditions an employee of a legal person may also represent other legal persons which have their principal place of business in a Contracting State and which have economic connections with the first legal person.
4. The Implementing Regulations may lay down special provisions concerning the common representation of parties acting in common.