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:int and 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.