In our November 1994 Newsletter we reported a decision of the Enlarged Board of Appeal of the European Patent Office holding that if a patent claim was not entitled to the relevant priority date, publication of the subject matter of the priority-founding application after the filing of that application could still be destructive of the novelty of the patent claim even though the disclosure made was identical to that which was contained in the application from which priority had been claimed. Such situations can arise where, for example, the patent claim is broader than that which was described in the priority document or in situations where for some reason the priority document itself is insufficient to establish the relevant date (for example, perhaps as a result of having defective drawings).

The United Kingdom patent law contained a provision that "for the avoidance of doubt" a patent shall not be invalidated by virtue of publication of a "relevant intervening act" which is defined as "an act done in relation to matter disclosed in the [priority application] between the date of the [priority application] and the application in suit ..., for example, making information available to the public about that invention ....". Notwithstanding this provision in the law, the English Patent Court has followed the Enlarged Board of Appeal of the European Patent Office on this issue. In the case of Belolt Technologies, Inc. v. Valmet Paper Machinery, Inc., the Court held that "the words 'for the avoidance of doubt' indicated that the provision was not intended to have substantive effect, Parliament clearly intended [the relevant provision] to implement the European Patent Convention ... If there are obscurities in a treaty, convention or EU directive it is too late to try to 'clarify' them in the UK implementing legislation".