Cc6 - 10 is standard, and there is a particular 10 that are usually used, if one of those is spoiled then they can substitute another. For example my 2nd DD started misbehaving during the last subtest of her first testing session (the tester routinely tested across two appts), testing stopped, that subtest was discarded and an allowable alternative added to the next session (which she ceilinged, perfect score).