Suppose that you have a stylesheet which customizes another stylesheet, perhaps changing the formatting of a few elements. Suppose that one of these elements is formatted by a complex template in the base stylesheet, and all you want to change is one small, special case. How can you do this?
The answer is with <xsl:apply-imports>:
...
<xsl:import href="basestyle.xsl"/>
...
<xsl:template match="table">
<xsl:choose>
<xsl:when test="@role='something-special'">
<xsl:call-template name="special-table-handler"/>
</xsl:when>
<xsl:otherwise>
<xsl:apply-imports/>
</xsl:otherwise>
</xsl:choose>
</xsl:template>