Determination of whether the disclosure of an invention in a European patent application is sufficient is dealt with in F‑III, 1 to F-III, 3.

The principles set out there will also apply mutatis mutandis to the opposition procedure. The overriding consideration in this context is the disclosed content of the European patent specification, that is to say what a person skilled in the art is able to derive directly and unambiguously from the explicit and implicit disclosure in the patent claims, description and drawings, if any, without using inventiveness. Pursuant to Art. 100(b), the patent has to disclose the invention in a manner sufficiently clear and complete for it to be carried out by persons skilled in the art. If the patent specification does not disclose the invention sufficiently clearly to enable it to be carried out over the full scope of the claim in accordance with Art. 100(b), this may be remedied, provided the original documents contained a sufficient disclosure, but subject to the condition that, as required under Art. 123(2), the subject-matter of the European patent does not extend beyond the content of the application as filed and, as required under Art. 123(3), the protection conferred is not extended.[Art. 100(b); ]

The skilled person wishing to implement the claimed invention reads the claims in a technically sensible manner. An objection of insufficient disclosure of the invention is therefore not to be based on embodiments that are meaningless and not consistent with the teaching of the application as a whole (see T 521/12).

There is normally no deficiency under Art. 100(b) if a feature which is essential for performance of the invention is missing from the claim but is disclosed in the description and/or drawings. However, unduly broad claims may be objected to under Art. 56 (see T 939/92).