GL-PCT A V 11.1 Chemical and mathematical formulae

The description, the claims and the abstract may contain chemical or mathematical formulae. Such formulae may be written by hand or drawn if necessary but it is recommended that appropriate drafting aids or materials, such as stencils or transfers, be used. For practical reasons formulae may be grouped together on one or more sheets in the description and paginated with it.

GL-PCT A V 11 Graphic forms of presentation not considered to be drawings

Where tables or chemical or mathematical formulae are included in the description, claims or abstract, they are not considered to be drawings and are thus not subject to the requirements for drawings.[]

11.1 Chemical and mathematical formulae

11.2 Tables

GL-PCT A V 10 Amendments to drawings

The drawings can be amended during the international phase only if the applicant files a demand for international preliminary examination. See GL/PCT‑EPO H‑I, 3.[Art. 34(2)(b); ]

For the rectification of obvious mistakes, see GL/PCT‑EPO B‑III, 2.3.2, and H‑I, 2.

GL-PCT A V 9 Conventional symbols

Known devices may be illustrated by symbols which have a universally recognised conventional meaning and are generally accepted in the art provided no further detail is essential for understanding the subject-matter of the claimed invention. Other signs and symbols may be used provided that they are not likely to be confused with existing conventional symbols, that they are readily identifiable (i.e. simple) and that they are clearly explained in the text of the description.

GL-PCT A V 8 Text matter in drawings

The drawings must not contain text matter, except a single word or words when absolutely indispensable, such as "water", "steam", "open", "closed", "section on AB" and, in the case of electric circuits and block schematic or flow sheet diagrams, a few short catchwords indispensable for understanding.

GL-PCT A V 7.6 Variations in proportions

Each element of each figure must be in proper proportion to each of the other elements in the figure, except where the use of a different proportion is indispensable for the clarity of the figure.[R. 11.13(g); ]

GL-PCT A V 7.5.5 Consistent use of reference signs in the drawings

A feature denoted by a reference sign must be denoted by the same sign throughout the international application.[R. 11.13(m); ]

GL-PCT A V 7.5.4 Consistent use of reference signs in the description, claims and drawings

Reference signs must be used in a manner which is consistent in the description, claims and drawings.

GL-PCT A V 7.5.3 Height of the numbers and letters in the drawings

The height of the numbers and letters must not be less than 0.32 cm. For the lettering of drawings, the Latin or, where customary, the Greek alphabet must be used.[R. 11.13(h); ]

GL-PCT A V 7.5.2 Arrows

Arrows may be used at the end of the reference lines provided that their meaning is clear.[]

– A free-standing arrow indicates the entire section towards which it points.

– An arrow touching a line indicates the surface shown by the line looking along the direction of the arrow.

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