L0: At least one private annotation, made public, such that it is useful for a greater community.
L1: A L0 annotation with questions, leading to responding answers or questions in form of annotations.
L2: A L1 annotation, supported by one local WikiEngine of the annotation-service provider, that delivers CommunityWiki:LinkLanguage context.
L3: A L2 annotation, supported by external WikiEngines, that create automatic backlinks on their annotating pages to the annotation. (AnnotationMediator?)
This page is WikAlong'ed.
This page has a DiiGo annotation
This page has an openmail:
DiiGo:  SocialAnnotation