better apilink description

htroot/Vocabulary_p.html

@@ -68,7 +68,7 @@ document.getElementById('apilink').setAttribute('href', 'Vocabulary_p.xml?' + wi
 //]]>
 </script>
 <span>The information that is presented on this page can also be retrieved as XML
-Click the API icon to see the XML.
+Click the API icon to see the RDF Ontology definition for this vocabulary.
 To see a list of all APIs, please visit the <a href="http://www.yacy-websuche.de/wiki/index.php/Dev:API">API wiki page</a>.</span>
 </div>
 #(/edit)#