Where a claim is vaguely formulated and leaves several constructions open as possibilities, and on one of these constructions part of the subject-matter claimed is not sufficiently described to be carried out, the claim is open to objection under Article 100(b) EPC. To avoid this objection the claim needs to be explicitly restricted to a construction which is also possible on the vague formulation of the claim, but which construction is not open to an Article 100(b) EPC objection. The mere fact that the description makes clear that this latter construction is the one intended does not mean that the claim can be treated as being confined to this latter construction. Article 69 EPC and its protocol were intended to assist a patent proprietor in contending for a broader interpretation of a claim than perhaps its wording warranted, not for cutting down the scope of a claim (see points 3.1 to 3.7).