to indicate that a particular work product or analysis is comprehensive, accurate, and/or capable of withstanding close scrutiny; suggestive of a shirt or uniform whose buttons have been fully fastened, without any having been missed, giving a neat and completed appearance, as in “Let’s make sure the presentation is buttoned-down before we send the final version to the senior team”; as this jargon can end with either “-up” or “-down”, it is a rare example of opposite terms with identical meanings