Macau
In Macau, there are two types of ID cards: Permanent Resident Identity Card (BIRP) and Non-Permanent Resident Identity Card (BIRNP). The identification number has 8-digit standard format: NNNNNNN(N), where N is a numeric digit 0-9. The first numeric digit N has special meaning, and it can be one of the following digits: '1', '5' or '7'.
'1': the first-time date of issuance of ID card to the bearer was 1992 or later.
'5': the predecessor of the ID card is Portuguese National Identity Card (BI), issued by Macau Civil Authority.
'7': the predecessor of the ID card is Macau Identity Card, issued by Macau Public Security Police.
During the Portuguese rule, Macau had no unified and rigid identification system, and several departments had the authority to issue different types of identity cards to Macau citizens and residents. Since 1992, the newly-established Identification Department (once known as SIM, now called DSI) has become the unitary authority to issue identity cards. It has adopted the above-mentioned numbering policy.
Macau's Finance Department has also adopted identification number as tax reporting number, for tax filing purposes.
Read more about this topic: National Identification Number