application by the holder a passport could be stamped so that this time was extended without reissue. Stamping for a further extension is not permitted at present. In the succeeding decades the periods of validity for adult applicants were gradually extended to three, five, and eventually ten years, the current standard. In 1981, the United States became the first country to introduce machine-readable passports. In 2000, the Department of State started to issue passports with digital photos, and as of 2010, all previous series have expired. In 2006, the Department of State began to issue biometric passports to diplomats and other officials. Later in 2006, biometric passports were issued to the public. Since August 2007, the department has issued only biometric passports, which include RFID chips. The United States participates in the Five Nations Passport Group, an international forum for cooperation between the passport issuing authorities in the United Kingdom, Canada, New Zealand, and Australia to "share best practices and discuss innovations related to the development of passport policies, products and practices". The United States Department of State has announced, and, in March 2021, started to issue, the next generation passport. The passport will have an embedded data chip on the information page protected by a polycarbonate coating; this will help prevent the book from getting wet and bending, and—should a passport be stolen—the chip will keep thieves from stealing personal information and falsifying an identity. The passport number will also be laser cut as perforated holes that get progressively smaller through pages—just one of several components of the "Next Generation" passport, including artwork upgrade, new security features such as a watermark, "tactile features," and more "optically variable" inks. Some designs on pages will be raised, and ink—depending on the viewing angle—will appear to be different colors. On November 18th, 2022, the Department of State announced that they are now issuing all passport books as Next Generation Passports. In June 2021, Secretary of State Antony Blinken announced that an option for American passport holders to select a third gender category on their passports was planned but would take time to implement. Additionally, applicants changing their gender would no longer be required to provide external documentation like a court order or medical certification. From April 11, 2022, the options listed on valid US Passport holders for sex/gender markers will be M, F and X—as announced formally by the Biden Administration within