1. A method of associating static data with one or more instances of XML elements of a desired data type, the method comprising: defining the desired data type as static data with a static-specifying data type definition in an XML schema, the static-specifying data type definition including: a first attribute identifying overridden data in an XML document when the static data is sub-typed, a second attribute specifying whether the static data is propagated in the XML document, and a third attribute specifying whether the static data is overridden when the static data is sub-typed; embedding an instance of an XML element of a pre-defined data type within annotation and appinfo elements of the static-specifying data type definition, the embedded XML instance representing the static data, and the static data of the instance of the XML element of the pre-defined data type applying to any other instances of elements of a data type including the static-specifying data type definition; and referencing the XML schema to obtain, from one XML document, the static data associated with the one or more XML instances of elements of the desired data type.