5.152. How should numbers, letters, reference signs and like indications be presented and applied to drawings? Numbers, letters and reference signs and any other data given on the sheets of drawings, such as the numbering of figures, and of the sheets of the drawings, acceptable text matter, graduations on scales, etc., must be simple and clear, and not used in association with any brackets, inverted commas, circles or outlines whatsoever. Signs indicating minutes, seconds or degrees are permitted. Numbers, letters and reference signs should be laid out in the same direction as the diagram so as to avoid having to rotate the sheet. Such numbers, letters and reference signs should not be so placed in the closed and complex parts of the drawings as to interfere with a thorough comprehension of the same, and therefore should rarely cross or mingle with the lines. As a general rule, numbers, letters and reference signs should be placed as closely as possible to the part in question.
5.153. A minimum size of 0.32 cm is required for all numbers and letters used on the drawings so that their reduction in size to two-thirds remains easily legible. The Latin alphabet should normally be used for letters. The Greek alphabet is to be accepted, however, where it is customarily used, for example, to indicate angles, wavelengths, etc.
5.154. Reference signs are to be used in a manner which is consistent as between the description, claims and drawings. In particular, reference signs not mentioned in the description must not appear in the drawings, and vice versa. Features of a drawing should not be designated by a reference sign in cases where the feature itself has not been described. This situation may arise as a result of amendments to the description involving the deletion of pages or whole paragraphs. One solution would be to delete reference signs on the drawing which have been deleted in the description. Where for any reason a figure is deleted, all reference signs relating solely to that figure appearing in the description and claims should also be deleted.
5.155. The same features, when denoted by reference signs, must, throughout the international application, be denoted by the same signs. However, where several variants or embodiments of a claimed invention are described, each with reference to a particular figure, and where each variant contains features whose function is the same or basically the same, the features may, if this is indicated in the description, be identified by reference numbers made up of the number of the figure to which it relates followed by the number of the feature, which is the same for all variants, so that a single number is formed. For example, the common feature “15” would be indicated by “115” in Fig. 1, while the corresponding feature would be indicated by “215” in Fig. 2, thereby allowing the individual feature and the figure on which it is to be considered to be indicated at the same time. Complex cases involving many pages of drawings may be made easier to read if, when the individual variants or embodiments are described with reference to particular groups of figures, the common reference sign is prefixed by the number of the particular variant or embodiment to which it relates; however, this should, if used, be explained in the description.
Date retrieved: 24 November 2017