In Brazil there are two systems. The first, the "Registro Geral" (RG) is a number associated to the official ID card. Although the ID cards are supposedly national, the RG numbers are assigned by the states and a few other organizations, such as the armed forces. So, not only is it possible for a person to have the same RG number as a person from other state (which is usually dealt with by specifying the state which issued the ID card), but it is also possible to (legally) have more than one RG, from different states.