Hi everyone, Here is the current text for the Extensibility section of the Specification. I've also included an example. Note 1: XMLSpy doesn't validate correctly attributes in element where you can have attributes from other namespace (i.e. doesn't flag errors). So for example, testing attribute in <trans-unit> is not working, but testing in <context> does, because <context> doesn't allow extra attributes. Note 2: Look at the current list of pre-defined attributes by opening xliff-values-1-1.xsd in a browser: the style sheet will display the values in a more frendly way. Read the notes in yellow and the places where there is '???' (they are unresolved issues). Note 3: I'm not too comfortable with the way to extend values. It's working this way, but I hope we can find a better mechanism. Maybe some help from XSD specialist is needed. Note 4: It's normal that the links in the excerpt won't work since the rest of the document is cut off. Cheers, -yves ps: FYI, I'll probably be slow with emails and not very productive next week (Unicode conference). Attachment: ExtensibilityExcerpt.zip Description: Zip compressed data