Hello, this is an example of setting a 404 by overwriting what the REST annotations would produce. I had to gathered pieces of specs together in order to have it working. Please tell me if I'm missing the documentation that cover this. Feedback are welcome. declare %rest:path("/categories/{$category}") %rest:GET %rest:produces("application/atomcat+xml") %output:omit-xml-declaration("no") %output:media-type("application/atomcat+xml") function page:category($category as xs:string) { if (db:exists('categories', $category || '.xml')) then doc('categories/' || $category || '.xml') else let $reason := "Category scheme not found" return <rest:response> <http:response status="404" reason="{$reason}"> <!--<http:header name="string" value="string"/>--> </http:response> <output:serialization-parameters> <output:omit-xml-declaration value="yes"/> <output:media-type value="text/plain"/> </output:serialization-parameters> </rest:response> }; Would produce the following on a not found document: HTTP/1.1 404 Not Found Content-Type: text/plain; charset=utf-8 Content-Length: 25 Server: Jetty(6.1.26) Category scheme not found -- Philippe