This attribute may be set on the
xsl:stylesheet element. The permitted values
are "yes" and "no". If set to "yes", the attribute enables the use of built-in types such as
xs:NCName that are not permitted under the W3C conformance rules for a Basic XSLT Processor.
This attribute has no effect under Saxon-SA, which already permits these types, under the conformance rules
for a Schema-Aware XSLT Processor.