1. A method for representing field structures in a markup language document, comprising: inputting at a computing device an application document that has been generated by a word-processing application that uses a file format that is specific to the application, wherein the file format is in a non-markup language format that is native to the application and the file format comprises unique properties for describing fields within the document, wherein the unique properties are defined by the application; determining at the computing device one or more unique properties corresponding to a field that relates to at least one section of the application document; determining at the computing device whether the field is a complex field or a simple field; mapping the determined properties of the field into at least one of a markup language element, an attribute, and/or a value, wherein the field is designated with a simple field markup language element when the field is determined to be a simple field; and storing at the computing device the mapped properties of the field in the markup language document whereby applications different from the application can understand the mapped field properties stored in the markup language document.