>   I guess selecting attributes in both apply-templates
> instructions is a typo?
>

Yes, sorry, mixing my metaphors. I meant to say:

> >   <xsl:template match="skos:altLabel|skos:prefLabel">
> >     <xsl:copy>
> >       <xsl:attribute name="xml:lang">en</xsl:attribute>
> >       <xsl:copy-of select="@*"/>
> >       <xsl:apply-templates select="node()"/>
> >     </xsl:copy>
> >   </xsl:template>
>
> >   <xsl:template match="*">
> >     <xsl:copy>
> >       <xsl:copy-of select="@*"/>
> >       <xsl:apply-templates select="node()"/>
> >     </xsl:copy>
> >   </xsl:template>

Note, I generally use the element-only form of identity template rather than
the elements-and-attributes form in the common case where all existing
attributes are to be copied to the output, without exception: or, as here,
where the exception is easily accommodated.

Regards,

Michael Kay
http://www.saxonica.com/
http://twitter.com/michaelhkay