Variable data documents can be considered as functions of their bindings to values, and this function could be arbitrarily complex to build strongly-customised but high-value documents. We outline an approach for editing such documents from example instances, which is highly configurable in terms of controlling exactly what is editable and how, capable of being used with a wide variety of XML-based document formats and processing pipelines, if certain reasonable properties are supported and can generate appropriate editors automatically, including web-service deployment. Publication Info: Submitted to ACM Symposium on Document Engineering, Sao Paulo, Brazil, Sept 2008