A companion document to the Strategic Approach document, this guide reviews the lessons learned from the various agency initiatives to integrate biodiversity issues into development cooperation programmes. The lessons learned have been condensed into a set of Guiding Principles which aim to ensure that development cooperation projects and programmes are effective and sustainable, and take full account of environmental security and biodiversity issues. Social, economic and institutional issues are an integral part of the Principles, since these are often the main underlying causes of biodiversity loss.