The purpose of this publication is to give guidance in the formulation of principles, criteria and indicators for sustainable forest management in all geographical regions. The hierarchical framework may serve as a manual to develop consistent standards. The first part of the publication provides an overview of the status of current developments in the field of certification. Various international and national fora and individual organisations have developed out standards for sustainable forest management for different purposes and spatial scales (global, national, regional, and the forest management unit). An annex to the main text of the document contains eleven existing standards, which makes this document a useful work of reference. The authors recognise the problem that existing standards appear to contain a wide range of interpretations of terms. As a consequence, the requirements of sustainable forest management as imposed by one standard are difficult to compare with the requirements of another standard. In addition, within existing standards inconsistency in use of terms may be found. Definitions of principles, criteria and indicators are lacking or are formulated too broadly. This may lead to insufficient coverage of the various aspects of sustainable forest management, possible overlap and to a redundancy of aspects dealt with. The presented framework was designed in an attempt to help to solve these problems and to promote the user-friendliness of principles, criteria and indicators. It was developed on the basis of several starting points and considerations. A distinction is made between input, process and outcome (performance/output) parameters. Also the notion of horizontal and vertical consistency is introduced. Horizontal consistency means that parameters (principles, criteria and indictors) at one hierarchical level have no overlap, while at the same time all aspects of sustainable forest management are covered. Vertical consistency means that the parameters are placed at the right hierarchical level, expressed in the correct terms, and linked to the appropriate parameters on the higher hierarchical level. Next, the function of each level in the hierarchical framework (principles, criteria and indicators) is made explicit. This function determines the way in which the parameters are formulated. Well-elaborated definitions of the hierarchical levels of principles, criteria and indicators are given. The document is illustrated with many examples, which facilitates the understanding of the concepts dealt with.