Guidelines play a vital role in the governance of professional practitioners in the frontline of the welfare state towards practices based on scientific knowledge. However the viability of guidelines as a genre of governing devices is by no means self-evident. This article interrogates the somewhat mysterious survival of one particular guideline. It suggests that explanations of the guideline's survival need to take into account how these governing devices, independent of their success or failure according to the part they are set to play, are producers of logics supportive to their own existence.