A Royal Warrant of Precedence is a warrant issued by the monarch of the United Kingdom to determine precedence amongst individuals or organisations.
Most warrants of this type are issued to grant a rank to a member of the nobility or gentry that they would normally have enjoyed when their relative (usually their sibling) inherits a title, but failed to assume automatically due to such circumstances as the death of their father (see courtesy title). The warrants are usually issued to the following effect:
Below is a list of such warrants in descending order of rank (note: the Order of Precedence for males and females is separate from one another):
References
Royal Warrant of Precedence Wikipedia(Text) CC BY-SA