The manner and order of presentation of the description should be that specified in Rule 42(1), i.e. as set out above, unless, because of the nature of the invention, a different manner or a different order would afford a better understanding and a more economic presentation. Since the responsibility for clearly and completely describing the invention lies with the applicant, the examiner should not object to the presentation unless satisfied that such an objection would be a proper exercise of his discretion.

Some departure from the requirements of Rule 42(1) is acceptable, provided the description is clear and orderly and all the requisite information is present. For example, the requirements of Rule 42(1)(c) may be waived where the invention is based on a fortuitous discovery, the practical application of which is recognised as being useful, or where the invention breaks entirely new ground. Also, certain technically simple inventions may be fully comprehensible with the minimum of description and only slight reference to prior art.