PCT International Search and Preliminary Examination Guidelines
15.29 The words of a claim must be read as they would be understood by a person skilled in the art in accordance with the meaning and scope which they normally have in the relevant art. See paragraphs 15.20 to 15.28 for guidelines regarding interpretation of particular claim types and features.
15.30 In two-part claims as defined by Rule 6.3(b) (known as “Jepson claims” under the practice of some Authorities), the claimed invention includes the limitations of the preamble in combination with the limitations in the characterizing portion of the claim. In these cases, the preamble is regarded as a limitation on the scope of the claim (see paragraph 5.22). In certain circumstances, it may be desirable to extend the subject matter of the international search to include the “technological background” of the claimed invention. This would include:
(i) the preamble portion of the claim, that is, the part preceding the expression “characterized by” or “the improvement comprising”;
(ii) the state of the prior art as explained in the introduction of the description of the international application but not identified by specific citations; and
(iii) the general technological background of the invention (often called “general state of the art”).
Combination of Elements
15.31 For claims characterized by a combination of elements (for example, A, B and C), the international search should be directed towards the combination; however, when searching classification units (see Chapter 7) for this purpose, sub-combinations, including the elements individually (for example, AB, AC, BC and also A, B and C separately), should be searched in those units at the same time. A search in additional classification units either for sub-combinations or for individual elements of the combination should only be performed if this is still necessary for establishing the novelty of the element in order to assess the inventive step of the combination.
15.32 When the international application contains claims of different categories that comply with the unity requirement (see Chapter 10), all these must be included in the international search. When the international application contains only claims of one category, it may be desirable to include other categories in the search. A reference describing a process of making a product but only claiming the product itself might only be classified in a subclass directed to the product and not be cross-referenced in a subclass directed to the process. Accordingly, when searching for a particular process of making a product it may be necessary to search for the product in order to discover the best prior art disclosing the process of making the product. As such, for example, except when the international application contains indications to the contrary, one may generally assume that in a claim directed to a chemical process, the starting products form part of the state of the art and need not be searched; the intermediate products will only be searched when they form the subject of one or more claims; but it is highly recommended that the final products always be searched, except when they are evidently known, since the most relevant prior art may only be classified in terms of the final products.