rdf-use-cases.md

 # Use cases für RDF
 
+## Relations to be discussed and semantically correct named
+### Variables
+- source Variable is the same variable as in the target study (wave)
+- source variable is annotated by a controlled vocabulary(ies)
+- source Variable is connected to a question
+- source variable is derived by target variable(s)
+
+### Question
+- source Question is in order next to the target question (Order within questionnaire)
+- source question is annotated by a controlled vocabulary
+- source question is annotated by a construct (controlled vocabulary)
+
+
 ## Use cases starting point
 
 - within DDI file linking (necessary)