The Official Geographic Code (COG) covers the whole of metropolitan France, the overseas regions and departments as well as countries and foreign territories. Several attribute files are made available each year :

• a file giving the list of municipalities, municipal districts, delegated municipalities and associated municipalities as of January 1st of the year, with the code of the higher levels (canton or pseudo-canton, department, region)

• a file giving the list of cantons and pseudo-cantons (fictitious canton with the outline of the entire municipality when it is shared between several cantons) on January 1st of the year

• a file giving the list of boroughs as of January 1st of the year

• a file giving the list of departments as of January 1st of the year

• a file listing the regions as of January 1st of the year

• a file giving the list of countries and foreign territories as of January 1st of the year

• a file giving the list of events that have occurred in the municipalities, municipal boroughs, associated and delegated municipalities since 1943 (this file corresponds to a passage table)

Since the availability of January 1, 2019, the GOC files have changed significantly in format and structure. They are now available in dBase format (ISO8859-15 encoding) and CSV (comma separator, UTF-8 encoding). The content of the French administrative division files (municipality, canton, arrondissement, department and region) has been simplified and standardized. The wording with article ("La Rochelle") has been added to the enriched wording, the capitalized wording and the article code. The historical file of the municipalities is replaced by a file of the movements of municipalities which gives the status of the municipalities before and after the events which affect them (fusion, creation of new municipalities, change of name...).

The files are accessible via the Metadata API, accessible on the api.insee.fr portal and on data.gouv.fr.