A.30 Filing date of application for patent Publication, observations and opposition 20. (1) The filing date of an application for a patent shall be the date on which the application is received by the Office if on the date of its receipt, the application contains — (a) an express or implicit indication that the grant of a patent is sought; (b) information which will enable the Registrar to establish the identity of the applicant and to contact him or her; (c) a part which, on the face of it, appears to be a description of the invention; and (d) a part which, on the face of it appears to be a claim of the invention. (2) For the purposes of establishing the filing date, information mentioned in 1 (a) may be filed in English or Setswana, provided that where the information is filed in Setswana, a translation into English shall be supplied by the applicant upon request by the Registrar. (3) Where the application does not comply with the requirements of subsection (1), the Registrar shall, in writing, request the applicant to supply the missing information, and the filing date shall be the date on which the missing information is received by the Office. (4) If an applicant fails to comply with any request made by the Registrar under subsection (2), the application shall be treated as though it had never been filed. (5) Where a part of the description of the invention appears to be missing from an application for a patent, or the application makes reference to drawings which are not included in the application, the Registrar shall request the applicant to furnish the missing part or drawings within such time as may be prescribed, and the filing date of the application shall be the date on which such part or drawings are received by the Office. (6) If the applicant fails to comply with any request made by the Registrar under subsection (5), the Registrar shall accord to the application the date on which the application was received by him or her, as the filing date, and shall treat any reference to such part or drawings as being non-existent. (7) Notwithstanding the provisions of subsection (6) and subject to the prescribed requirements, a reference, made in the application to a previously filed application shall, for the purposes of establishing the filing date of the application, replace the description and any drawings. 21. (1) Upon the expiry of 18 months, counted from the date of filing the application for a patent with the Registrar or, where relevant, from the applicable priority date, the Registrar shall, in the prescribed manner and subject to payment of the prescribed fee by the applicant, publish the application in the Journal and thereafter the application shall be open for public inspection. (2) The applicant may request, in writing, for the application to be published before the expiry of the period under subsection (1) and subject to compliance with the requirements for publication, the Registrar shall publish the application as requested.