[Guzzman]

Serving Royal Navy officers who joined the Royal Naval Air Service retained the crown and foul anchor on their cap badges and buttons instead of wearing the crown and eagle. These officers were relatively few in number and most joined when the RNAS was first established. Officers who directly entered the RNAS wore buttons and cap badges bearing the eagle design and would never have worn the crown and foul anchor design. So both types of button could have been worn by RNAS officers - it simply depended upon whether or not they were a Royal Navy officer prior to joining the RNAS.

Pete