We have a client that wants to specify both these attributes in an XML header. Is this allowed under XML specs ? An example is given below. <InvoiceImport xmlns="http://www.xxxx.com/schema/auditor/mws/invoice/" xmlns:xsi="http://www.w3.org/20...Schema-instance" xsi:noNamespaceSchemaLocation="http://www.xxxx.com/schema/auditor/mws/invoice/invoice-1.1.xsd" xsi:schemaLocation="http://www.xxxx.com/schema/auditor/mws/invoice/ http://www.xxxx.com/schema/auditor/mws/invoice/invoice-1.1.xsd">