And the answer is that my network connection died ;-) WS-A talks in terms of EPRs with extensible header information and ReferenceProperties (WS-A 2004) and ReferenceParameters. Only the latter two (or one, depending on your version) are meant to be opaque to the consumer and used only by the EPR minter. The EPR isn't opaque though. Like all WS-* specifications and standards, we didn't say anything about language bindings: we are implementation language agnostic. However, I do find it strange that information like To, RelatesTo and MessageId aren't available through the Java API. I don't recall that being part of JSR 261 (before it died), so maybe this is something that is under specified in JAX-WS? But the conclusion is: it's not a problem with WS-A :-) View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4142843#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...