The <xsl:otherwise> element is used to define the action that should be taken when none of the <xsl:when> conditions apply. It is similar to the else or default case in other programming languages.
<xsl:otherwise>
TEMPLATE
</xsl:otherwise>None.
None.
Subinstruction, must appear as the last child of an <xsl:choose> element, within a template.
XSLT, section 9.2
Supported.