The READ-XML( ) method can find and use XML Schema from the following sources, in the order defined below:
1. The XML Schema specified with the schema-location option of the READ-XML( ) method. If this option is used, XML Schema references embedded in XML data are ignored.
2. A <schema> child element of the root element of the XML data document. Provided the method does not specify a schema-location, then any one or combination of this and the remaining list item are used.
3. An xsi:schemaLocation or xsi:noNamespaceSchemaLocation attribute on an instance data in the XML data document.
4. If no schema is present, the READ-XML( ) method will attempt to infer schema.
