The dependent claim in multiple forms may contain a reference, in the alternative only, to more than one claim previously set forth and then specify a further limitation of the subject matter claimed. A multiple dependent claim shall be construed to incorporate by reference all the limitations of the particular claim in relation to which it is being considered.
A multiple dependent claim refers back to more than one preceding claim. In addition, each multiple dependent claim is treated as the number of claims on which it is dependent so that a multiple dependent claim dependent on two other claims is treated as two claims.
A multiple dependent claim shall not serve as a basis for any other multiple dependent claim. In other words, it is not permissible to have a multiple dependent claim dependent upon another multiple dependent claim. A multiple dependent claim can be dependent only upon a number of single dependent claims. A claim such as “An apparatus as in claims 1, 2, 3, or 4, made by a process of claims 5, 6, 7, or 8” is improper. In turn, only a single dependent claim can be dependent upon a multiple dependent claim. In US patent law, the statutory section 35 U.S.C. 112(e) authorizes multiple dependent claims in applications as long as they are in the alternative form. For example, “An apparatus according to claims 3 or 4, comprising —” is permissible. However, cumulative claiming, e.g., “An apparatus according to claims 3 and 4, comprising —” is not permitted.
A special one-time fee is payable for any multiple dependent claim in the application. Every single dependent claim dependent upon a multiple dependent claim is for fee purposes treated as the same number of claims as the multiple dependent claim. It is almost always possible to break a multiple dependent claim into single dependent claims. For fee reduction purposes and clarity of claiming, in the U.S. form, it is better to have single dependent claims, rather than multiple dependent claims. But the claim drafter is free to use multiple dependent claims that are acceptable.