user doc: Add limitation that a field that is a collection cannot be in a conditional mapping expression.
@@ -30,7 +30,10 @@ endif::[]
The data mapper supports expressions that are similar to a Microsoft
Excel expressions, but does not support all Microsoft Excel expression
-syntax.
+syntax. In this release, a conditional expression that refers to a field
+that is a collection causes an error. It is expected that a future
+release will support a conditional expression that refers to a field that
+is a collection.
You can define zero or one condition for each mapping.
