Directorate-General The Gendarmerie headquarters, called the Directorate-General of the National Gendarmerie ( (DGGN))), long located in downtown Paris, relocated in 2012 to the southern suburb of Issy-les-Moulineaux. The Directorate-General of the national gendarmerie includes: The general staff, divided into offices and services, The inspector-general of the Gendarmerie (I.G.G.N.) Three main directorates Human Resource directorate (D.P.M.G.N.) Finance and Support directorate (D.S.F.) Operations directorate (D.O.E.)—The general, chief of the Operations directorate, has authority on: Organisation and evaluation subdirectorate, International co-operation subdirectorate, Defence and public order subdirectorate, Public safety and road traffic safety subdirectorate, Criminal Investigation subdirectorate. Two joint Gendarmerie/Police offices Joint Information systems office (ST(SI)2) Joint purchasing office (SAELSI) Organization The main components of the organization are Departmental Gendarmerie, Mobile Gendarmerie, Republican Guard, Overseas Gendarmerie, five specialized Gendarmerie branches, Provost Gendarmerie and Intervention Group of the National Gendarmerie. The above-mentioned organizations report directly to the Director General (DGGN) with the exception of the Republican Guard, which reports to the Île-de-France region. Departmental Gendarmerie The Departmental Gendarmerie (), also named «La Blanche» (The White), is the most numerous part of the Gendarmerie, is in charge of policing small towns and rural areas. Its territorial divisions are based on the administrative divisions of France, particularly the departments from which the Departmental Gendarmerie derives its name. The Departmental Gendarmerie carries out the general public order duties in municipalities with a population of up to 20,000 citizens. When that limit is exceeded, the jurisdiction over the municipality is turned over to the National Police. It is divided into 13 metropolitan regions (including Corsica), themselves divided into (one for each of the 100 , thus the name), themselves divided into (one for each of the 342 arrondissements). It maintains gendarmerie brigades throughout the rural parts of the territory. There are two kind of brigades: Large autonomous territorial brigades (BTAs) Brigade groups composed of smaller brigades supervised by a larger one (COBs). In addition, it has specialised units: Research units, who conduct criminal investigations when their difficulty exceeds the abilities of the territorial units Surveillance and intervention platoons (PSIGs), who conduct roving patrols and reinforce local units as needed. Specialized brigades for prevention of juvenile delinquency Highway patrol units. Mountain units, specialised in surveillance and search and rescue operations, as well as inquiries in mountainous areas In addition, the Gendarmerie runs a national criminal police institute () specializing in supporting local units for difficult investigations. The research units