These words are used as a mark of recognition to show that a manufacturer or shopkeeper supplies goods to certain members of the Royal Family.
The sign is a plague bearing the Royal Coat of Arms of HM the Queen, HRH The Duke of Edinburgh, HM The Queen Mother or HRH The Prince of Wales with the words By Appointment to and then the name of the relevant royal person.
The coat of arms is displayed on the shop or factory of the supplier. It is also shown on their headed paper and on the sides of delivery vans.
The system of By Appointment to has been in existence since the Middle Ages.
To receive Royal Appointment the supplier must have been providing the goods or service for at least 5 years to the appropriate member of the Royal Family.
It is only open to tradesmen and shopkeepers, not professionals like doctors.
Once awarded the Royal Appointment can be removed, recent removals have been Harrods (wonder why??!) and Benson & Hedges cigarettes.
Royal Appointment can be awarded to any size of trader, it is not restricted to just large organisations.
A trader can ask for Royal Appointment by applying to the Lord Chamberlain's office.
http://www.royalwarrant.org/