Sch. PATENTS ACT (as amended) (c) the delay in accepting the specification was not due to any neglect or default on the part of the applicant: Provided that if, within twenty-one months from the date of the lodging of the complete specification, the applicant, by notice accompanied by the prescribed fee, so requires, the said period of eighteen months shall be extended to such period, not exceeding twenty-one months from the date of the lodging of the complete specification, as may be specified in that notice. (2)* If, at the expiration of the period allowed under subsection (1), an appeal to the Tribunal is pending under any of this Act in respect of the application or, in the case of an application for a patent of addition, either in respect of that application or in respect of the application for the patent for the main invention, or the time within which such an appeal could be brought in accordance with Part X, apart from any future extension of time thereunder, has expired, then— (a) where such an appeal is pending or is brought within the time aforesaid or before the expiration of any extension of that time granted, in the case of the first extension, on an application made within that time or, in the case of a subsequent extension, on an application made before the expiration of the last previous extension, the said period shall be extended until such date as the Tribunal may determine; (b) where no such appeal is pending or is so brought, the said period shall continue until the end of the time aforesaid or, if any extension of that time is granted as aforesaid, until the expiration of the extension or the last extension so granted. 16 Acceptance and publication of complete specification and cancellation thereof (1) Subject to section fifteen, the complete specification may be accepted by the Registrar at any time after the applicant has complied with the requirements imposed upon him by this Act: Provided that the applicant may give notice to the Registrar requesting him to postpone acceptance until such date, not being later than eighteen months from the date of lodging of the complete specification, as may be specified in the notice and the Registrar may postpone acceptance accordingly. (2) Subject to subsection (5), on the acceptance of a complete specification the Registrar shall give notice to the applicant who shall, within the prescribed period or within such further period as the Registrar may allow, advertise in the Journal the fact that the specification has been accepted and, unless the acceptance of the specification is so advertised, the application shall lapse. (3) Upon advertisement in terms of subsection (2) the application form, the specification and the other documents essential to obtain acceptance which were lodged in pursuance thereof shall be open to public inspection unless the acceptance of the complete specification has been cancelled in terms of subsection (5) before such advertisement. (4) After the date of the publication in terms of subsection (2) of notice of acceptance of a complete specification and until the sealing of a patent in respect thereof, the applicant shall have the like privileges and rights as if a patent for the invention had been sealed on the date of the publication of the notice unless the acceptance of the complete specification has been cancelled in terms of subsection (5) before that date. (5) If so requested before the advertisement in the Journal in terms of subsection (2) of the acceptance of a specification, the Registrar may at any time prior to the publication of such advertisement cancel in the prescribed manner the acceptance of that complete specification and on such cancellation he shall— (a) make a note thereof in the Register; and (b) if the advertisement of the acceptance is subsequently published in the Journal, cause notice of the cancellation of the acceptance of the specification to be published in the Journal. (6) The cancellation of the acceptance of a complete specification in terms of subsection (5) shall not preclude the Registrar from re-accepting that complete specification at a later date if at the time the applicant requested the cancellation he also gave notice to the Registrar such as is referred to in the proviso to subsection (1). 17 Opposition to grant of patent (1) Any person interested, including the State, may within three months from the date of the advertisement of the acceptance of a complete specification which has not been cancelled in terms of subsection (5) of section sixteen or within such further period as the Registrar, on application made to him within the said period of three months, may allow, or, with the consent of the applicant, at any time before the sealing of the patent, oppose the grant of a patent in accordance with this section by giving written notice to the registrar of the Tribunal of opposition to such grant on any of the following grounds and no others— (a) that the applicant is not a person entitled under section six to make the application; (b) that the application is in fraud of the rights of the person giving such notice or of any persons under or through whom he claims; (c) that the invention does not relate to an art, whether producing a physical effect or not, process, machine, manufacture or composition of matter which is capable of being applied in trade or industry; (d) subject to section twenty-six, that the invention is obvious in that it involves no inventive step having regard to what was common knowledge in the art at the effective date of the application; (e) that the invention, in so far as is claimed in any claim of the complete specification, is not useful; (f) that the complete specification does not fully describe and ascertain the invention and the manner in which it is to be performed; (g) that the claims of the complete specification do not sufficiently and clearly define the subject-matter for which protection is claimed; (h) that the complete specification does not disclose the best method of performing the invention known to the applicant at the time when the specification was lodged at the Patent Office; (i) that the application form or any other document filed in pursuance of the application contains a material misrepresentation; (j) that the matter described or claimed in the complete specification is not the same as that described in the provisional specification, and— (i) in so far as it is not described in the provisional specification, was not new at the date when the complete specification was lodged at the Patent Office; or (ii) forms the subject of a pending application made in Zimbabwe for a patent the effective date of