According to the specification for XInclude, processors must add an
attribute to elements included from locations with a different base URI. Without
these attributes, the resulting infoset information would be incorrect. Unfortunately,
these attributes make XInclude processing not transparent to Schema validation.
One solution to this is to modify your schema to allow
attributes to appear on elements that might be included from different base URIs.
There is a similar problem with
xml:lang attributes that are added as a result
of language fixup. If the addition of
is undesired by your application, you can disable
base URI fixup and
language fixup so that
these attributes will not be added.