¹[21. (1) Subject to the other provisions of this section, a patent shall have to all intents the like effect as against the Government as it has against any person. (2) The officers or authorities administering any department of Government may, by themselves or by such of their agents, contractors or others as may be authorised in writing by them, at any time after the application , and after giving notice to the applicant or patentee, make, use or exercise the invention for the service of the Government on such terms as may, either before or after the use thereof, be agreed on, with the approval of the Government between such officers or authorities and the applicant or patentee, or, in default of agreement, as may be settled in the manner hereinafter provided. And the terms of any agreement or license concluded between the applicant or patentee and any person other than such officers or authorities, shall be inoperative so far as concerns the making, use or exercise of the invention for the service of the Government. (3) Where an invention which is the subject of any patent has, before the date of the patent, been duly recorded in a document by, or tried by or on behalf of, the officers or authorities administering any department of Government (such invention not having been communicated directly or indirectly by the applicant or patentee), such officers or authorities, or such of their agents, contractors, or others, as may be authorised in writing by them, may, after giving notice to the applicant or patentee, make, use or exercise the invention so recorded or tried for the service of the Government, free of any royalty or other payment to the applicant or patentee, notwithstanding the existence of the patent. If, in the opinion of such officers or authorities, the disclosure to the applicant or patentee, as the case may be, of the document recording the invention, or the evidence of the trial thereof, if required, would be detrimental to the public interest, it may be made confidentially to counsel on behalf of the applicant or patentee, or to any independent expert mutually agreed upon. (4) In the event of any dispute as to the making, use or exercise of an invention under this section, or the terms therefor, or as to the existence or scope of any record or trial as aforesaid, the matter shall be referred to the High Court Division for decision, who shall have power to refer the whole matter or any question or issue of fact arising thereon to be tried before a special or official referee or an arbitrator upon such terms as it may direct. The Court, referee or arbitrator, as the case may be, may, with the consent of the parties, take into consideration the validity of the patent for the purposes only of the reference and for the determination of the issues between the applicant or patentee and such officers or authorities. The Court, referee, or arbitrator, further, in settling the terms as aforesaid, shall be entitled to take into consideration any benefit or compensation which the applicant or patentee, or any other person interested in the patent, may have received directly or indirectly from the Government or from such officers or authorities in respect of such patent: Provided that, if the inventor or patentee is a Government servant and the subject-matter of the invention is certified by the Government to be connected with work done in the course of such service, any such dispute shall be settled by the Government after hearing the applicant or patentee and any other person having an interest in the invention or patent. (5) The right to use an invention for the services of the Government under the provisions of this section, or any provisions for which this section is substituted, shall include, and shall be deemed always to have included, the power to sell any articles made in pursuance of such right which are no longer required for the services of the Government. (6) Nothing in this section shall affect the right of the Government or of any person deriving title directly or indirectly from the Government to sell or use any articles forfeited under any law for the time being in force relating to customs or excise.