If they are used then even if the manufacturer had a published standard it wouldn'`t be very useful.
Measure voltage discard any 0v. Charge them fully (using a proper charger, do the bulk charge slowly say 500ma, and preferably in a suitable explosion containmemt container, check after a few minutes to be sure it is accepting a charge), disconnect let sit for a week and remeasure, it shouldn't have dropped too much (testing self discharge), use a cc discharge at 1a and measure capacity down to 3v, decide if that meets your needs or it's too low capacity to be useful, you might go to 2.7v but diminishing returns.
If it loses more than 0.2v in a week from 4.2v I'd say trash, if it's capacity is less than 600mAh not really worth it, and if it never completes charging obviously trash., but if it charges, holds, and has a decent capacity at 1a, all good, charge it back to a storage level and put it in your stash (suitable explosion containment stash of course!)