where an entry stamp would be placed by an immigration official. Frequent border crossing residents, such as lorry drivers, were required to replace the booklet every few months due to the lack of pages for entry and exit stamps. The booklets were eventually phased out. In 1999, the permit was changed into its current credit-card-like form and the official name has also changed to its current name, following the handover of sovereignty of both territories. A new version came to circulation in 2013 with enhanced security features and an embedded biometric chip. Appearance The current and older permits are credit card-sized which makes it more efficient to carry in one's wallet. The older permit is also machine readable, which facilitates entry into Mainland China at any manned immigration checkpoint or through self-service immigration gates (currently available at Hong Kong-Shenzhen, Macau-Zhuhai crossings, Beijing West Railway Station, and international airports throughout Mainland China). These gates scan the permits with an optical reader and use the software to verify one's biometric informations, such as thumb prints and facial scans, with the database. After the inspection is completed, the person is released. Starting from 2 January 2013, the current version of the permit came to circulation. The design of newer permits has been changed. A biometric chip, like the one used on biometric passports, was added to the permit. The numbering scheme of the permit has been revamped: the previous 11-digit permit number has been separated to a 9-digit permit number and a 2-digit issuing sequence number. The permits now also have an English description which reads "This card is intended for its holder to travel to the mainland of China", and it was added because holders of the older version may have difficulties to board flights outside the Greater China Region as no English description was given on the older permit. The Simplified Chinese name of holder on his or her Hong Kong or Macau Identity Card appears on the front of the permit, whereas the original Traditional Chinese name of holder appears on the back of the permit. The issuing authority of this permit have been changed from Public Security Bureau of Guangdong to the Bureau of Exit and Entry Administration of the Ministry of Public Security. Validity Most permits for adults are valid for 10 years; minors under 18 years old are issued permits valid for five years. Temporary permits are