+
+/*
+
+// see also : ftp://medical.nema.org/medical/dicom/final/cp343_ft.doc
+
+RELATIONSHIP BETWEEN DIRECTORY RECORDS
+
+Directory Record Type Directory Record Types which may be included
+ in the next lower-level directory Entity
+
+(Root Directory Entity) PATIENT, TOPIC, PRIVATE
+
+PATIENT STUDY, PRIVATE
+
+STUDY SERIES, VISIT, RESULTS, STUDY COMPONENT, PRIVATE
+
+SERIES IMAGE, OVERLAY, MODALITY LUT, VOI LUT, CURVE,
+ STORED PRINT, RT DOSE, RT STRUCTURE SET, RT PLAN,
+ RT TREAT RECORD, PRESENTATION, WAVEFORM, SR DOCUMENT,
+ KEY OBJECT DOC, SPECTROSCOPY, RAW DATA, PRIVATE
+
+IMAGE PRIVATE
+OVERLAY PRIVATE
+MODALITY LUT PRIVATE
+VOI LUT PRIVATE
+CURVE PRIVATE
+STORED PRINT PRIVATE
+RT DOSE PRIVATE
+RT STRUCTURE SET PRIVATE
+RT PLAN PRIVATE
+RT TREAT RECORD PRIVATE
+PRESENTATION PRIVATE
+WAVEFORM PRIVATE
+SR DOCUMENT PRIVATE
+KEY OBJECT DOC PRIVATE
+SPECTROSCOPY PRIVATE
+RAW DATA PRIVATE
+
+TOPIC STUDY, SERIES, IMAGE, OVERLAY, MODALITY LUT, VOI LUT,
+ CURVE, STORED PRINT, RT DOSE, RT STRUCTURE SET,
+ RT PLAN, RT TREAT RECORD, PRESENTATION, WAVEFORM,
+ SR DOCUMENT, KEY OBJECT DOC, SPECTROSCOPY, RAW DATA,
+ PRIVATE
+
+VISIT PRIVATE
+
+RESULTS INTERPRETATION, PRIVATE
+
+INTERPRETATION PRIVATE
+STUDY COMPONENT PRIVATE
+PRIVATE PRIVATE, (any of the above as privately defined)
+MRDR (Not applicable)
+
+Note : Directory Record Types PRINT QUEUE, FILM SESSION, FILM BOX, and
+ IMAGE BOX were previously defined in DICOM. They have been retired.
+ See PS 3.3-1998.
+*/
+