11. A method comprising: generating, from a markup language document containing: a markup language element hierarchy having a parent markup language element and a contained set of markup language elements; and a plurality of references to said markup language element hierarchy, each of said plurality of references being a further markup language element having an attribute identifying said parent markup language element of said markup language element hierarchy, another markup language document containing one instance of said set of markup language elements for each of said plurality of references, wherein said parent markup language element has an attribute with a unique value, wherein said attribute of said further markup language element identifies said parent markup language element by said unique attribute value, and wherein said generated markup language document lacks said parent markup language element.
11. A method comprising: generating, from a markup language document containing: a markup language element hierarchy having a parent markup language element and a contained set of markup language elements; and a plurality of references to said markup language element hierarchy, each of said plurality of references being a further markup language element having an attribute identifying said parent markup language element of said markup language element hierarchy, another markup language document containing one instance of said set of markup language elements for each of said plurality of references, wherein said parent markup language element has an attribute with a unique value, wherein said attribute of said further markup language element identifies said parent markup language element by said unique attribute value, and wherein said generated markup language document lacks said parent markup language element. 12. The method of claim 11 wherein said markup language is Extensible Markup Language (XML), said markup language document is an XML document, said set of markup language elements is a set of XML elements, and the generated markup language document is another XML document.