The use of XML has become pervasive. It is used in a range of data storage and data exchange applications. In many cases such XML data is captured from users via forms or transformed automatically from databases. However, there are still many situations where users must read and possibly write their own XML documents. There are a variety of both commercial and free XML editors that address this need. A limitation of most editors is that they require users to be familar with the grammar of the XML document they are creating. A better approach is to provide users with a view of a document’s grammar that is integrated in some way to aid the user. In this paper, we formalise and extend the design of such an editor, Xeena for Schema. It uses a grammar tree view to explicitly guide user navigation and editing. We identify a key property that such an editor should have, stable reversable navigation, then via our formal treatment extend the Xeena for Schema design to satisfy it.