Literate

Able to read and write (default: in native tongue; but can be applied to literacy in a particular language)

Probably one of the third things to be looked for in royalty, after making sure that they're breathing and checking their teeth (to make sure no substitution has occurred [Nyrond Enterprises sell a useful dental engraving tool, by which you can mark, identify and copyright your Royalty -- ask your local Nyrond for details])