Article 70⁶³, ⁶⁴
Authentic text of a European patent application or European patent

(1) The text of a European patent application or a European patent in the language of the proceedings shall be the authentic text in any proceedings before the European Patent Office and in any Contracting State. 

(2) If, however, the European patent application has been filed in a language which is not an official language of the European Patent Office, that text shall be the application as filed within the meaning of this Convention. 

(3) Any Contracting State may provide that a translation into one of its official languages, as prescribed by it according to this Convention, shall in that State be regarded as authentic, except for revocation proceedings, in the event of the European patent application or European patent in the language of the translation conferring protection which is narrower than that conferred by it in the language of the proceedings. 

(4) Any Contracting State which adopts a provision under paragraph 3:

(a) shall allow the applicant for or proprietor of the patent to file a corrected translation of the European patent application or European patent. Such corrected translation shall not have any legal effect until any conditions established by the Contracting State under Article 65, paragraph 2, or Article 67, paragraph 3, have been complied with;

(b) may prescribe that any person who, in that State, in good faith has used or has made effective and serious preparations for using an invention the use of which would not constitute infringement of the application or patent in the original translation, may, after the corrected translation takes effect, continue such use in the course of his business or for the needs thereof without payment.