Disclosure of the invention

Description must be clear

5.126 The description should be drafted in language that would be clear to the person skilled in the art. Unnecessary or irrelevant material should be avoided (Francis’ Application 27 RPC 87). Similarly, discussion of the principles behind the invention and other material such as background calculations are unnecessary unless they are required for a full understanding of the invention. However, no objection should be taken unless the additional discussion is unduly extensive.

5.127 As the specification is addressed to a person skilled in the art it is therefore acceptable for a description to use art-specific technical terms. However, the use of these terms must be consistent with the recognised meaning – a different meaning should not be given to a term if it is likely to be unclear to the skilled reader. Nevertheless, the language used in the specification should be readily understandable to the skilled person. Where the invention is difficult to explain, such as where it is so ground breaking that standard nomenclature is not yet available, then some allowance may be given (Natural Colour Kinematograph Co Ltd v Bioschemes Ltd 32 RPC 256 at page 269).

5.128 An opening statement or ‘consistory clause’ setting out the nature of the invention is normally included in the description. The consistory clause may, however, be omitted if the description indicates explicitly or implicitly and without ambiguity the essential feature of the invention.

5.129 If it becomes necessary for the applicant to restrict the scope of the main claim in order to meet an objection of prior publication, any corresponding statement of invention should be similarly restricted as the applicant can then no longer allege the broad statement to be the invention. A claim which is wider in scope than the statement of invention may be open to objection on the grounds that it is not supported by the description. An objection based on a lack of support may not be overcome by the addition of further examples or features to the specification since this is prohibited under Section 84, however, an objection to the excessive breadth of the claims may be remedied by restricting the scope of the claims.