This is an archived snapshot of W3C's public bugzilla bug tracker, decommissioned in April 2019. Please see the home page for more details.
Section 26.2 says This feature requires an extension to the serializer described in [XSLT and XQuery Serialization]. The intended reading is "the serializer described in [XSLT and XQuery Serialization]" not "an extension ... described in [XSLT and XQuery Serialization]" The reader who follows the link to the serialisation spec looking for a description of the extension will be disappointed. The simplest fix is perhaps to change the sentence to read: This feature requires that the serializer described in [XSLT and XQuery Serialization] be extended as follows.
I have made the suggested change (silently, as it is purely editorial).