3.1 Certificate of exhibition; identification of invention 

Where an applicant states when filing an application that the invention which is the subject of the application has been displayed at an official or officially recognised international exhibition falling within the terms of the Convention on international exhibitions, they must file a certificate of exhibition within four months of the filing of the European patent application. The exhibitions recognised are published in the EPO's Official Journal. The certificate must:

(a)have been issued during the exhibition by the authority responsible for the protection of industrial property at that exhibition 

(b)state that the invention was exhibited at the exhibition 

(c)state the opening date of the exhibition and the date of the first disclosure, if different from the opening date of the exhibition 

(d)be accompanied by an identification of the invention, duly authenticated by the above-mentioned authority.