Peer review is the cornerstone of scientific publishing. But it isn’t always clear exactly what Nature Physics expects of its referees. The journal explains in its November Editorial (5, 775; 2009). “Whatever you think about a paper, it is vital to explain to us exactly why you think it. Your colleagues among the other reviewers may disagree with your assessment, and we do not base our decisions on a show of hands. Hence detailed critiques carry more weight in informing our decisions than terse affirmations one way or the other (in most cases we would disregard the latter, regardless of who supplied it).