An object lesson

This is what happens if you think you know a word. Confronted with a request for a notarized receipt for 160 rubles in неплатежные денежные знаки, I built a whole story up about a note of hand or possibly bank draft gone astray and the issuer's fear of it falling into the wrong hands, basing that story on what I thought those неплатежные денежные знаки were.

Problem is, неплатежный doesn't mean "uncashed", or "unpaid". (And I should have known that right off, because the adjectival -н- doesn't have a passive feeling about it.) No, as I discover upon actually doing some looking around, a неплатежный денежный знак is an "untenderable (unusable) bank note" - damaged or defaced.

The writer didn't want to pay a second time without notarized proof that the first payment had actually contained unusable bills...

Moral: if the word's unfamiliar, it never hurts to look it up even if you suspect you know what it means...