If the claims in an application relating to and describing in detail an automatic telephone exchange are directed to an automatic communication switching centre, the search should not be extended to automatic telegraph exchanges, data switching centres etc. merely because of the broad wording of the claim, but only if it is probable that such an extended search could produce a document on the basis of which a reasonable objection as regards lack of novelty or inventive step could be established.
If a claim is directed to a process for manufacturing an "impedance element" but the description and drawings relate only to the manufacture of a resistor element, and give no indication as to how other types of impedance element could be manufactured by the process of the invention, extension of the search to embrace, say, manufacture of capacitors would not normally be justified.
If the main claim relates to the chemical treatment of a substrate, whereas it appears from the description or all the examples that the problem to be solved is solely dependent on the nature of natural leather, it is clear that the search should not be extended to the fields of plastics, fabrics or glass.
If the description and drawings are directed to a lock with a safety cylinder whereas the claims refer to a device allowing the indexation of the angular position of a first element with respect to two other rotating elements, then the search should be limited to locks.
In exceptional cases where the lack of disclosure or support is such as to render a meaningful search over the whole of the scope of the claim(s) impossible, application of the procedure for an incomplete search or a declaration taking the place of a search report under Rule 63 may be appropriate (see B‑VIII, 3).