This is root element of this document which contains name space definitions for the document elements. It's a referenced element. For detailed description, please refer referenced element doc. It's a referenced element. For detailed description, please refer referenced element doc. Description is not available. The unique identifier of the differentiator. Provide an extension hook to customize XDiffIDRef. Provide an extension hook to localize XDiffIDRef. This type can hold a string of max length of 10 characters.