 However, a person not having either their residence or place of business within the territory of one of the EPC Contracting States (a "non-European party") "must be represented by a professional representative and act through him in all proceedings", except for filing a European patent application.Proceedings include grant proceedings (as applicant), opposition proceedings (as patentee, opponent or intervener pursuant to ), limitation and revocation proceedings (as patentee), and appeal proceedings (as appellant or respondent).Representation of persons who must be represented and persons who need not be represented but want to be represented must be by a professional representative, or, if the party is a "European party", the representation may be by an authorised employee or by a legal practitioner.