Disclosed is a method (700) of creating a security document (310), the method comprising the steps of encoding the document (310) with a first set (309) of protection marks containing information defining an absolute co-ordinate system (314) across the face of the document (310), and encoding the document (310) with a second set (302) of protection marks containing information that (i) identifies at least one region (605) of the document (310) according to the co-ordinate system (314) and (ii) defines at least one security attribute of the content within the defined region (605), wherein the first (309) and second (302) sets of protection marks are intermixed across the face of the document (310) and are used together to determine the location of the defined region (605) within the document.