10. A computer-readable storage medium for representing fields in a markup language document, comprising: inputting an application document that has been generated by a word-processing application that uses a non-markup language file format that is specific to the application; determining properties relating to one or more fields used within the application document, wherein the field comprises unique properties are defined by the application; determining whether the field is one of a complex field and a simple field; writing the properties into at least one of a markup language element, an attribute, and 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 the properties in the markup language document such that the fields of the application document are substantially maintained when the markup language document is parsed by an application that is different from the application used to generate the application document.
14. The computer-readable storage medium of claim 10 , wherein an instruction portion of the field excludes richly formatted content and embedded additional fields when the field is a simple field.