DOCBOOK: <xref> to <glossary>

Aren't  <xref>'s to <glossary> allowed? 
I have a document on DocBook where I talk about glossaries. And, as
the output example, I'd like to make a link to the glossary I'm
using. Unfortunately, I receive a message stating that xref's to
glossary are unsupported. 
Is it another bug like the xref to section or it's really the way it
gotta be? 

Thanks!
--
Godoy.	<>               GPG Fingerprint
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"Ser poeta não é minha ambição,          E932 1330 BE6D A4A3 0625 
 é minha maneira de estar sozinho"
              - Fernando Pessoa.       Publicações @ Conectiva S.A. 

Except where explicitly stated I speak on my own behalf.
Exceto onde explicitado as declarações aqui feitas são apenas minhas.