What does NEC4 clause 60.1(10) mean?

Clause 60.1(10) allocates the cost of a fruitless search. The event is that the Supervisor instructs the Contractor to search for a Defect and no Defect is found. It has one exception: the search was needed only because the Contractor gave insufficient notice of doing work that obstructed a required test or inspection, in which case the Contractor pays for the search whatever it finds. If the Supervisor's suspicion was wrong the Client pays for testing it; if the Contractor covered up work the Supervisor was entitled to inspect, the Contractor pays for uncovering it. To bring an event within the paragraph the Contractor shows the Supervisor's instruction to search, what the search involved, and the outcome recorded by the Supervisor showing no Defect; where a Defect was found in part of the search, only the part where none was found is within the paragraph. It should also show it gave the notice the Scope required before covering the work, because the exception turns on that. The event arises from the Supervisor's instruction, so the Project Manager notifies it, but the outcome is not known until the search is complete, so in practice the Contractor should notify under clause 61.3 as soon as the search is closed with nothing found rather than rely on the Project Manager. The change to the Prices is assessed under clause 63.1 as the effect of the instruction on the actual Defined Cost of work done by the date of the instruction and the forecast Defined Cost of work not yet done, plus the Fee: opening up, testing, making good and standing time. What most often goes wrong is that the Supervisor's record of the outcome is not obtained, so a later argument arises about whether something minor found during the search was a Defect. Any delay to the Completion Date is assessed separately under clause 63 by the programming expert.