The border between the language areas is the so-called Belgian language or linguistic border.[27] It is based on the actual language border between the sprachräume but is not utterly identical.[28][29] Through constitutional reforms in the 1970s and 1980s, regionalisation of the unitary state led to a three-tiered federation: federal, regional, and community governments were created, a compromise designed to minimize linguistic, cultural, social and economic tensions.[30][31] The authority of the Regions and Communities is limited to some language areas: