Biennial Update Reports. Documents containing updates of national greenhouse gas inventories, including national inventory reports and information on mitigation actions, needs and recieved support. At COP16 the Parties to the UNFCCC decided that developing countries (non-Annex I Parties), in line with their capabilities and the level of support provided for reporting, should also submit BURs. And at COP17 guidelines for the preparation of BURs by non-Annex I Parties where adopted. Developed countries are required to submit a biennial report (BR) as a part of their national communication (NC) or as a separate report every two years. Developing countries are required to submit their BURs every two years (see also ICA and National Communication).