Hi, when using "uri" tag in a sgml docbook document, po4a-updatepo complains with "Unknown tag URI" e.g. <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook V4.5//EN"> <book> <chapter> <title>foo</title> <para> See <uri type="homepage"i>www.whatever.org</uri>. </para> </chapter> </book> FWIW it validates with "onsgmls -s file.sgml" It got introduced in docbook 4.3 (cf http://docbook.org/tdg/en/html/uri.html) -- Frédéric Delanoy