A claim may also contain a reference to another claim even if it is not a dependent claim as defined in Rule 29(4). One example of this is a claim referring to a claim of a different category (e.g. "Apparatus for carrying out the process of claim 1 ...", or "Process for the manufacture of the product of claim 1 ..."). Similarly, in a situation like the plug and socket example of III, 3.2(i), a claim to the one part referring to the other co-operating part (e.g. "plug for co-operation with the socket of claim 1 ...") is not a dependent claim. In all these examples, the examiner should carefully consider the extent to which the claim containing the reference necessarily involves the features of the claim referred to and the extent to which it does not.

In the case of a claim for a process which results in the product of a product claim, if the product claim is patentable then no separate examination for the novelty and non-obviousness of the process claim is necessary (see IV, 9.12), provided that all features of the product as defined in the product claim inevitably (cf. IV, 9.12) result from the claimed process (see III, 4.4, and T 169/88, not published in OJ). This also applies in the case of a claim for the use of a product, when the product is patentable and is used with its features as claimed (see T 642/94, not published in OJ). In all other instances, the patentability of the claim referred to does not necessarily imply the patentability of the independent claim containing the reference. It should also be noted that if the process, product and/or use claims have different effective dates (see C-V, 1 and 2), a separate examination may still be necessary in view of intermediate documents.