When using call number found on member copy in OCLC WorldCat generally accept the call number as is unless you notice a problem.
When checking to see if it is a duplicate call number, that is if we already assigned it to another book, try to notice any problems. For example, if a call number has 2 cutter numbers, but all the ones under the same class number in Voyager have only one, there may be a mistake. Pass over to one of the professional catalogers to check.