(3) Only one side of each sheet contained in the application shall be used. (4) All elements of the application shall be on paper which is flexible, strong, white, smooth, nonshiny and durable. (5) The size of the sheets shall be A4 (29.7 cm. x 21 cm.), but the registrar may accept sheets of other sizes. (6) Subject to regulation 21(3) of these Regulations, the minimum margins of sheets shall be as follows— (a) upper margin of each page, except the first page: 20 mm.; (b) upper margin of the first page: 30 mm.; (c) side margin adjacent to the bindings: 25 mm.; (d) other side margin: 20 mm.; and (e) bottom margin: 20 mm. (7) All sheets shall be numbered at the top of the sheet and in the middle, in consecutive Arabic numerals. (8) In effecting the sequential numbering of the sheets, the elements of the application shall be placed in the following order— (a) the request; (b) the description; (c) the claims; (d) the abstract; and (e) the drawings. (9) The sequential numbering of the sheets shall be effected by using three separate series of numbering as follows— (a) the first series shall apply to the request only and shall commence with the first sheet of the request; (b) the second series shall commence with the first sheet of the description and continue through the claims until the last sheet of the abstract; and (c) the third series shall apply to the sheets of the drawings only and shall commence with the first sheet of the drawings. (10) In the application, every fifth line of each sheet of the description and the claims shall be numbered in Arabic numerals placed to the left of the relevant lines but to the right of the margin.