A markup language document has data entry fields corresponding to markup language nodes that are arranged in a hierarchical structure of parents having child nodes. The hierarchical position of each markup language node in the hierarchical structure is expressed as a corresponding fragment of the markup language. For each parent, a markup language fragment is formed so as to have a plurality of portions each corresponding to the fragment of a respective child node without repeating any fragment of the respective child nodes. Portions that respectively correspond to the child nodes are used for data entry with the data entry fields, where an electronic form is displayed on a user interface for interactive data entry. The electronic form has one or more data entry fields each corresponding to one of the data entry fields of the structured markup language document and into which data can be entered.