Regulation 9—Claims.(1) Where an application contains several claims they shall be numbered consecutively in arabic numerals.(2) The definition of the subject matter for which protection is sought shall be in terms of the technical features of the invention.(3)  Claims shall be written either—(a) in two parts, the first part consisting of a statement indicating those technical features of the invention which are necessary in connection with the definition of the claimed subject matter and which in combination appear to be part of the prior art; the second part ("the characterizing portion"), introduced by the words "characterized in that," "characterized by," "wherein the improvement comprises," or other words to the same effect, consisting of a statement concisely indicating those technical features which, in combination with the features stated in the first part, define the subject matter for which protection is sought; or(b) in a single statement containing a recitation of a combination of several elements or steps, or a single element or step, which defines the matter for which protection is sought.(4)  No claim shall contain, in respect of the technical features of the invention, references to the description or any drawings, for example, such references as: "as described in part ... of the description," or "as illustrated in ... of the drawings," unless such a reference is a necessary feature for the understanding of the claim or enhances the clarity or the conciseness of the claim.(5)  No claim shall contain any drawing or graph except tables and chemical or mathematical formulas.(6)  Where the application contains any drawing, any technical feature mentioned in any claim may, if the intelligibility of that claim can be enhanced, include a reference sign to that drawing or to the applicable part of that drawing; a reference sign shall be placed between square brackets or parentheses and shall not be construed as limiting the claim.(7) A claim which includes all the features of one or more claims of the same category hereinafter referred to as a "dependent claim" or "multiple dependent claim," respectively shall preferably first refer to the other claim by indicating the serial number of the other claim or the serial numbers of the other claims and then state those features claimed that are additional to the features claimed in the other claim.(8) Dependent claims or multiple dependent claims may depend on dependent claims or multiple dependent claims.  Multiple dependent claims may refer in the alternative or in the cummulative to the claims on which they depend.(9) All dependent claims referring to the same other claims and all multiple dependent claims referring to the same other claims, shall be grouped in the most practical way possible.