Validating svg file
One bit of code I did today changes the way validator.w3handles doctype-less SVG: it used to be passed to the opensp (DTD) engine and I'm experimenting sending it to I believe that: * There is little point in making DTDs for newly developed languages.I am not an expert, but given the limitations of DTDs and given how Web languages tend towards mix-and-match (with or without namespaces), DTDs just don't seem to fit.Specific to your case it would seem that simply the closing statement for the switch is missing, which may have to do with the file being rather large and possibly having gotten truncated on save.element, as is common practice for Inkscape-generated content, and tried to validate it.
There are other combo options that the validator claims to understand, including XHTML RDFa, XHTML 1.1 plus Math ML 2.0, XHTML 1.1 plus Math ML 2.0 plus SVG 1.1. More concretely, are there specific problems that make that difficult?
Once you start mixing XML dialects, a DTD based validator can't help you.