Dont they usually also put an abbreviated version on the nose gear doors . And the tail 'numbers' G-BOAC , N1234 , A4E-EK style are surely part of the formal registration process of the aircraft, country of registration and ownership. Another example is Bermuda VP-B which despite being one of the smallest countries in the world ( 23 Sq Miles is the worlds largest offshore registry for airline and private aircraft . So the 'tail number still has an important place