A "multiple dependent claim" is a claim which depends on more than one previous claim, for example, "The apparatus of any one of claims 1 to 3...". Similarly, a "multiple multiple dependent claim", shortened by the Japan Patent Office to a "Multi-Multi Claim", is a multiple dependent claim which depends on another multiple dependent claim.
On 1 April 2022 the Japan Patent Office (JPO) stopped accepting Multi-Multi Claims in newly filed applications. The reason given by the JPO was:
"For the purpose of promoting international harmonization as well as reducing the workload of examination and the burden of monitoring by third parties".
International harmonization likely refers to making the JPO similar to other major patent offices, such as China, Korea, and the US which already have restrictions on Multi-Multi Claims. Indeed, just three months after the new restriction, the ratio of applications containing Multi-Multi Claims to those not containing Multi-Multi Claims fell from 65% to about 5% (statistic published by the JPO).
While it appears that many attorneys in Japan have changed how they write applications, there are concerns that the changes could make Japan applications less effective as a basis for priority in other offices, particularly the EPO (European patent office).
The reason for these concerns is that it is advantageous for an EPO application to include Multi-Multi claims, because this makes it easier to amend the application after filing to combine features. Specifically, if a first claim refers to a second claim, then an amendment can be filed which combines the features in those claims, so it is preferable to have as many such claim references as possible to give the maximum freedom for amendments. Previously, because both the EPO and JPO allowed Multi-Multi claims, an EPO application could claim priority from a JP application with the same set of Multi-Multi Claims. However, if the text of the Japanese priority document does not include Multi-Multi claims, and it is amended to produce Multi-Multi Claims for an EPO application, the priority claim might not be effective for all the claim combinations. Furthermore, unless the Multi-Multi claims are added before the EPO application is filed, the EPO may refuse the amendment, considering it adds subject matter.
Fortunately, this headache can be avoided by including text in the description of the JP application which is the desired Multi-Multi Claims without using the word "claims" (e.g. using the word "aspect" or "clause" instead). In this case, if the same description is used for the JPO and EPO patent applications, Multi-Multi claims can be added to the EPO application (before filing or afterwards) without adding matter and without compromising the priority claim. Even though the EPO requires the deletion of these "claim-like clauses" before an application can proceed to grant, they can be quickly removed without legal consequences.
As for the reasons the JPO have given for changing their practice, the question remains: if the JPO felt a driving force to "promote international harmonization" by removing Multi-Multi claims, are the EPO and other countries which presently allow them (e.g. the UK) also under pressure to no longer allow Multi-Multi Claims?
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