(a) Amendments to the claims under Article 19 or Article 34(2)(b) may be made either by cancelling one or more entire claims, by adding one or more new claims or by amending the text of one or more of the claims as filed. Where a claim is cancelled, no renumbering of the other claims shall be required. In all cases where claims are renumbered, they shall be renumbered consecutively in Arabic numerals.
(b) The applicant shall, in the letter referred to in Rule 46.5(b) or Rule 66.8(c), indicate the differences between the claims as filed and the claims as amended or, as the case may be, differences between the claims as previously amended and currently amended. He shall, in particular, indicate in the said letter, in connection with each claim appearing in the international application (it being understood that identical indications concerning several claims may be grouped), whether: