Distinguished Service Order DSO
Instituted by Queen Victoria on 6th September 1886, it is now awarded to officers of all three branches of the Armed Forces, and also to officers of the Mercantile Marine Service, for meritorious or distinguished service whilst on active duty.
Nominations may only be made if the person concerned has been mentioned in despatches.
Imperial Service Order ISO
King Edward VII instituted this Order on 8th August 1902 in recognition of faithful service by members of the clerical and administrative staff of the Civil Service in the UK and in the Dominions, Colonies and Protectorates.
The Order has only one class, that of Companion, and holders may add the letters ISO after their names.