rdf-use-cases.md

@@ -2,7 +2,9 @@
 
 ## Relations to be discussed and semantically correct named
 
-Described potential relations go in both directions and need to be named.
+Described potential relations go in both directions and need to be named. Some relations
+are predefined by the "within" DDI structure, like question and answer or variable and question. Other relations connect DDI documents, like variable in waves. Other relations go
+to outside elements, like variable is tagged by a controlled vocabularies. 
 
 ### Variables
 - source variable is the same variable as in the target study (wave)
@@ -24,6 +26,7 @@ Described potential relations go in both directions and need to be named.
 
 ### Variable & Question
 - source variable is connected to question(s)
+  - possible names: annotatedByControlledVocabular