While the issue of standards has received attention from analysts in science and technology studies, this attention has tended to focus on either units of measurement or compatibility standards. Much less attention has been devoted to equally important standards of practice. These are the procedural or process standards which govern how technologists go about designing and constructing artifacts. Such standards have a substantial documented history in the form of engineering codes of practice. As the embodiment of judgments rendered by a (...) particular community of technological practi tioners, these standards both reflect and shape the exercise of practitioner judgment. This article explores both these functions through examples drawn from structural and software engineering. These examples yield insights regarding both the role of formal procedural standards in technological practice and the unusual nature of software technology. (shrink)