use of xml:lang

I looking for a way to allow a textual element occurs several times with 
different xml:lang attribute values.

Something as (multiple <name> allowed for a <country>):
<country>
  <name>brazil</name>
  <name xml:lang="fr">brésil</name>
  <name xml:lang="es">brasil</name>
</country>
Or better (one only <name> allowed for a <country>):
<country>
  <name>
    <language>brazil</language>
    <language xml:lang="fr">brésil</language>
    <language xml:lang="es">brasil</language>
  </name>
</country>

I'm currently thinking of a key to ensure unicity, but is it not overkill ?
<key name="languageKey">
    <selector xpath="country/name"/>
    <field xpath="@xml:lang"/>
</key>
or
<key name="languageKey">
    <selector xpath="country/name/language"/>
    <field xpath="@xml:lang"/>
</key>
And i doubt it will allow a default value (without xml:lang attribute) in 
either case.

Am i missing something there ?
-- 
Guillaume Rousse <rousse@ccr.jussieu.fr>
GPG key http://lis.snv.jussieu.fr/~rousse/gpgkey.html