Six broad land-use categories form the basis of estimating and reporting greenhouse gas emissions and removals from land use and land-use conversions. The land uses may be considered as top-level categories for representing all land-use areas, with sub-categories describing special circumstances significant to emissions estimation, and where data are available. The categories are broad enough to classify all land areas in most countries and to accommodate differences in national land-use classification systems, and may be readily stratified (e.g., by climate or ecological zones). The categories (and sub-categories) are intended to be identified through use of Approaches for representing land-use area data described in subsequent sections.