PCT International Search and Preliminary Examination Guidelines


Appendix to Chapter 5

Interpretation of Claims

A5.20  The International Searching and Preliminary Examining Authorities have divergent practices with regard to whether the description can provide special definitions of terms that are used in the claims. Either of the alternative guidelines below may be relied upon by an International Authority as appropriate.

A5.20[1]  Where the description provides a special meaning by way of, for example, defining a term appearing in the claim, that definition should be used for the interpretation of the claim. The claims should not be limited in their meaning by what is explicitly disclosed in the description and drawings. The claims should not be limited by the scope of the examples of the claimed invention contained in the description. Further, if the wording of the claims needs interpretation, the description and the drawings, and the general knowledge of a person skilled in the art on the filing date are taken into account.

A5.20[2]  If the description gives the words in a claim a special meaning, the examiner should, so far as possible, require the claim to be amended whereby the meaning is clear from the wording of the claim alone. The claim should also be read with an attempt to make technical sense out of it. Such a reading may involve a departure from the strict literal meaning of the wording of the claims.

Use” Claims

A5.21  In some International Searching and Preliminary Examining Authorities, for purposes of international search and examination, a “use” claim of the form such as “the use of substance X as an insecticide” or “substance X when/whenever used as an insecticide” should be regarded as equivalent to a “process” claim of the form “a process of killing insects using substance X.” (However, it should be noted that in certain designated/elected States, “when/whenever used” claims are considered for the purposes of the national law to be improper process claims which lack clarity and constitute excluded subject matter.) Before such Authorities, a claim of the form indicated should not be interpreted as directed to the substance X recognizable (for example, by further additives) as intended for use of an insecticide. Similarly, a claim for “the use of a transistor in an amplifying circuit” would be equivalent to a process claim for the process of amplifying, using a circuit containing the transistor and should not be interpreted as being directed to “an amplifying circuit in which the transistor is used,” nor to “the process of using the transistor in building such a circuit.”