Municipalities can choose the level of control among several different methods. They have the authority to either formulate a plan local d'urbanisme (or PLU, a local uiban plan that includes detailed land-use regulations and sets the zones where construction is permitted) or a carte communale (the municipality map demarcating areas where construction is permitted), depending on the context of the municipality. Construction in green fields is only possible when allowed by the PLU or by the carte communale, and municipalities must otherwise comply with the national principle of limiting construction.