2.3 XML Schema Files (XSD) Specification
The XML schema documents in the form template (.xsn) file MUST conform to [XMLSCHEMA1].
This section specifies the XML schema documents representing the XML schema for the data of any form files based on the form template. The specific XML schema documents affected are specified by the documentSchema element of the form definition (.xsf) file specified in section 2.2.1.2.42.
In this section, the following terms are used as specified in [XMLSCHEMA1]:
constraining facet
namespace prefix
XSD
XSD data type
XSD schema
In section 2.3.1, the "xs" and "xsd" namespace prefixes in all XSD fragments MUST be associated with the "http://www.w3.org/2001/XMLSchema" namespace.