def listUsedAnnotations(rootdirectory):
     annotationlist = []
     
     projects = File.allProjects(rootdirectory)
     for project in projects:
         projectannotations = Metadata.getAnnotations(project)
         for projectannotation in projectannotations:
             if not projectannotation in annotationlist:
                 annotationlist.append(projectannotation)
     
     return annotationlist