How validating parsers use xml schema namespace
Some parsers can also validate the document against a schema.
Validates the XML string/file against the specified XSD string/file.
The validator will report fatal errors, non-fatal errors and warnings.
If the XSD is publicly available using HTTP and referenced through a "schema Location" or "no Namespace Schema Location", then the validator will pick it up and it doesn't need to be specified/uploaded.
At the moment, my validation fails immediately because the xmlns version number in the incoming XML doesn't match the one I'm using.
I want to ignore this version number and go ahead and validate the remainder of the XML.
Relax NG and Schematron are two other validation methods worth being familiar with.
Choose your DTD namespace approach depending on what you’re trying to accomplish with your DTD.
The default namespace approach is easier if you’re not mixing namespaces and just want a simple validation.
In your DTD you generally have to choose a single namespace declaration method because of the weak namespace support*.
Here’s the DTD from the above sample modified for namespaces declared in two different ways: namespace prefix.