RTFM: section 3.2 from FAQ: http://www.aleksey.com/xmlsec/faq.html BTW, "id-6516276" is not an ID according to XML specification. Aleksey > func=xmlSecXPathDataExecute:file=xpath.c:line=273:obj=unknown:subj=xmlXPtrEval:error=5:libxml2 library function failed:expr=xpointer(id('id-6516276'))