Jamming all GPD properties in a single attribute seems quite complex to me. How about a nested optional element in the jPDL namespace to contain the GPD properties separately? For example: <state> | <gpd width="100" length="100" color="fuschia" /> | </state> Advantages: * Because the gpd element is optional, there is no need for a separate GPD namespace. * You do not need to jam different GPD properties in a single attribute. * The contents of the gpd element can be described in a schema, so you get code completion and validation at parsing time. This is not possible with a single attribute. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4192169#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...