Considering the post that started this thread, maintaining the current semantics without using default attribute values would require an explicit "xlink:type='simple'" on every <titleInfo>, <relatedItem>, <name>, etc. *even if no "href" attribute is present*. It might be worthwhile to re-think whether these elements are always, or merely sometimes, simple XLinks. (Just saying. FWIW I don't see the problem with default attribute values in the schema.) --Andy >>> [log in to unmask] 05/04/05 10:48 AM >>> > I'd change it to required, and then update it to optional if the W3 > adopts 1.1. So you would advocate mandating that every occurrence of xlink:href="xxx" be explicitly accompanied by xlink:type="simple"?