18.1       Residence and Nationality

(a)  Subject to the provisions of paragraphs (b) and (c), the question whether an applicant is a resident or national of the Contracting State of which he claims to be a resident or national shall depend on the national law of that State and shall be decided by the receiving Office.

(b)  In any case, 

(i)  possession of a real and effective industrial or commercial establishment in a Contracting State shall be considered residence in that State, and

(ii)  a legal entity constituted according to the national law of a Contracting State shall be considered a national of that State.

(c)  Where the international application is filed with the International Bureau as receiving Office, the International Bureau shall, in the circumstances specified in the Administrative Instructions, request the national Office of, or acting for, the Contracting State concerned to decide the question referred to in paragraph (a). The International Bureau shall inform the applicant of any such request. The applicant shall have an opportunity to submit arguments directly to the national Office. The national Office shall decide the said question promptly.

18.2       [Deleted]

18.3       Two or More Applicants

If there are two or more applicants, the right to file an international application shall exist if at least one of them is entitled to file an international application according to Article 9.

18.4       Information on Requirements under National Law as to Applicants

(a) and (b)  [Deleted]

(c)  The International Bureau shall, from time to time, publish information on the various national laws in respect of the question who is qualified (inventor, successor in title of the inventor, owner of the invention, or other) to file a national application and shall accompany such information by a warning that the effect of the international application in any designated State may depend on whether the person designated in the international application as applicant for the purposes of that State is a person who, under the national law of that State, is qualified to file a national application.