In this respect, the UK Presidency has put forward a proposal for EU-wide use of biometrics in national ID cards." in French) are issued, although they may also carry a passport, a work permit or a (temporary) residence permit.
In some countries the possession of a government-produced identity card is compulsory while in others it may be voluntary.
In countries which do not have formal identity documents, informal ones may in some circumstances be required.
These cards are issued by the same organization responsible for driver's licenses, usually called the Department of Motor Vehicles.
For the Sahrawi people of Western Sahara, pre-1975 Spanish identity cards are the main proof that they were Saharaui citizens as opposed to recent Moroccan colonists.
Those working on UK railway lands near working lines must carry a photographic ID card to indicate training in track safety (PTS and other cards) possession of which is dependent on periodic and random alcohol and drug screening.