diff --git a/dspace-spring-rest/src/main/java/org/dspace/app/rest/model/SelectableMetadata.java b/dspace-spring-rest/src/main/java/org/dspace/app/rest/model/SelectableMetadata.java
index 7123d83b3b..7d3c91f20c 100644
--- a/dspace-spring-rest/src/main/java/org/dspace/app/rest/model/SelectableMetadata.java
+++ b/dspace-spring-rest/src/main/java/org/dspace/app/rest/model/SelectableMetadata.java
@@ -12,7 +12,14 @@ import com.fasterxml.jackson.annotation.JsonInclude.Include;
 
 /**
  * The SelectableMetadata REST Resource. It is not addressable directly, only
- * used as inline object in the InputForm resource
+ * used as inline object in the InputForm resource.
+ * 
+ * SelectableMetadata was introduced to make a clear distinction between the
+ * cases where a value-pairs was used as an authority list of acceptable values
+ * (dropdown) and where it was used to allow to pick the metadata to use to
+ * store the value (qualdrop_values). If a value-pair is used by a
+ * qualdrop_value it is not autoregistered as an authority, instead
+ * it is exposed as an array of SelectableMetadata object
  * 
  * @author Andrea Bollini (andrea.bollini at 4science.it)
  *