Working on the Mariage files, I discovered an oddity in the validation of SVG code. Chris Lilley of the W3C had written to me before Christmas, pointing out that I was using svg:id attributes on rect elements, when I should be using an unqualified id attribute. He was correct; however, I've now discovered that using plain id results in a failure to validate against the SVG 1.1 schema I'm using. This schema is an XSD file generated by Trang from the W3C's official DTD; they don't provide an SVG version at all. However, our code does validate against the DTD for SVG 1.1, so it seems that it's the schema, not the XML, that's wrong; and the error seems to have been introduced by the Trang conversion. This is not a major issue, but it's annoying. I've written to Chris Lilley to ask him if there's a standard XSD release of the SVG 1.1 standard, but I'm not hopeful; we may have to try to debug the XSD file we have, and fix the problem that way.