The purpose of this guidance is to provide information aimed primarily at national governments that may wish to consider implementing a PRTR system. The manual gives a set of options for how to implement the various principles underlying an effective PRTR system. Conditions within each country will dictate the precise details of how a specific national PRTR system will develop in practice. The guidance is organised along five main themes, including: major issues in deciding whether to establish a PRTR; formulating goals/objectives and a list of substances for a PRTR; data handling and management issues; making PRTR outcomes publicly accessible and implementing a full PRTR system.