Class hierarchy

    http://www.w3.org/2000/01/rdf-schema#Resource 
        nie:DataObject 
        ╰── nfo:FileDataObject 
            ╰── nfo:EmbeddedFileDataObject nfo:EmbeddedFileDataObject 
                ├── nmo:MimePart ├── ────┐
            │   │                        │
                ╰── ╰── nfo:Attachment ──┤
                                         └── nmo:Attachment