Flag Carrier is a term used to describe a person or organization that is responsible for the transportation and display of a nation's flag. The term is often used to refer to airlines, which are responsible for carrying the national flag on their aircraft. The term can also be used to refer to other organizations, such as the military, which are responsible for displaying the national flag in various locations. The term Flag Carrier is often abbreviated to REF, which stands for 'Responsible for the Exhibition of Flags'.