The Director General of the Institute shall rule on the application for invalidity or revocation in the light of all the written and oral observations submitted, if any, by the parties.
At any time during the proceedings, by express request:
1° The applicant for invalidity may waive one or more of the grounds invoked or limit the scope of his application to some of the goods or services invoked or referred to;
2° The applicant for revocation may limit the scope of his application to some of the goods or services referred to.