Vaccination requirements for international travel are the aspect of vaccination policy that concerns the movement of people across borders. Countries around the world require travellers departing to other countries, or arriving from other countries, to be vaccinated against certain infectious diseases in order to prevent epidemics. At border checks, these travellers are required to show proof of vaccination against specific diseases; the most widely used vaccination record is the International Certificate of Vaccination or Prophylaxis (ICVP or Carte Jaune/Yellow Card). Some countries require information about a passenger's vaccination status in a passenger locator form.