Hi, I have downloaded the schemas from http://schemas.opengis.net/ows/0.3.2/. The schemas refer to xlink which I already have on my system in e:/downloads/GML3.1/GML2004-10-29/xlink/xlinks.xsd. Rather than change the schemaLocation in the ows19115subset.xsd file I thought that I would use a catalog file to tell Oxygen 5.0 to find a local copy. The default catalog file in "Options => Preferences => XML Catalog" is file:/C:/Program Files/Oxygen 5.0/frameworks/catalog.xml. I edited this file by adding the following line: <nextCatalog catalog="e:/downloads/oxygencatalog.xml"/> and added the following lines in the e:/downloads/oxygencatalog.xml" file: <?xml version="1.0" encoding="UTF-8"?> <catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"> <rewriteURI uriStartString="http://www.w3.org/1999/xlink/" rewritePrefix="GML3.1/GML2004-10-29/xlink/"/> </catalog> If I open all the ows schemas into a project and then try to validate the project I get the following error: http://www.w3.org/TR/xmlschema-1/#src-resolve E src-resolve: Cannot resolve the name 'xlink:simpleLink' to a(n) 'attribute group' component. ows19115subset.xsd file:/E:/downloads/ows2/ows19115subset.xsd 111:43 Yet the "simpleLink" attribute group is defined in xlinks.xsd as follows: <attributeGroup name="simpleLink"> <attribute name="type" type="string" fixed="simple" form="qualified"/> <attribute ref="xlink:href" use="optional"/> <attribute ref="xlink:role" use="optional"/> <attribute ref="xlink:arcrole" use="optional"/> <attribute ref="xlink:title" use="optional"/> <attribute ref="xlink:show" use="optional"/> <attribute ref="xlink:actuate" use="optional"/> </attributeGroup> Am I not using the catalog file syntax properly or is there a mismatch between the ows XSDs and xlink? Thanks. John Hockaday Geoscience Australia GPO Box 378 Canberra ACT 2601 (02) 6249 9735 http://www.ga.gov.au/ john.hockaday\@ga.gov.au