We argue in this note that the principles of validity need fresh understanding to explain the elements of private ordering exhibited in the vast swathes of informal markets around the world. Informal markets, by definition, lie outside formal legal systems and yet display a tenacious stability in their norms. We show that these norms are valid because they are driven by reputation rather than any higher order of law. In doing so, reputation drives efficacy into validity. By remolding Kelsen's ideas on validity into Hart's internal point of view, we show how reputation drives efficacy into validity. We illustrate this idea through a case study on a centuries-old footwear cluster in Agra (India).