in figure ________ of the drawings”. 20. Interpretation of claims. (1) The description and the drawings may be used to interpret the claims, and the claims shall be clear and concise and fully supported by the description. (2) Any claim submitted after the filing date of the application and which is not identified by the claims previously appearing in the application shall, at the choice of the applicant, be submitted either as an amended claim or as a new claim. (3) The deletion of any claim previously appearing on the application shall be made by indicating the number of the previous claim followed by the word “cancelled”. (4) Where the application contains drawings, the technical features mentioned in the claims shall whenever practicable be followed by the reference signs relating to those features. (5) When used, the reference signs shall be placed between parentheses; but if inclusion of reference signs does not particularly facilitate quicker understanding of a claim, they shall not be used. (6) It is permissible to include in the same application two or more independent claims of the same category which cannot be readily covered by a single generic claim. (7) It is permissible to include in the same application a reasonable number of dependent claims claiming specific forms of the invention made in an independent claim. 21. Drawings. (1) Drawings shall be required as part of the application for a patent when considered necessary for the understanding of the invention. (2) Drawings forming part of an application for a patent shall be on sheets, the usable surface area of which shall not exceed 26.2 cm. by 17 cm.