| Attributes | att.canonical (@key, @ref) 
                        
                        
                        
                           | role | may be used to specify further information about the entity referenced by
                              this name, for example the occupation of a person, or the status of a place. |  
                           | nymRef | (reference to the canonical name) provides a means of locating the canonical form
                              (nym) of the names associated with the object
                              named by
                              the element bearing it. 
                                 
                                    | Status | Optional |  
                                    | Datatype | 1–∞ occurrences of 
                                       separated by whitespace |  
                                    | Values | One or more valid identifiers, separated by
                                       whitespace. |  
                                    | Note | 
                                             The value must point directly to one or more XML elements
                                          by means of one or more URIs, separated by whitespace. If more
                                          than one is supplied, the implication is that the name
                                          is associated with  several distinct canonical names.
                                        |  |  |