7. The method of claim 5 , wherein the visual feedback comprises an indication that a sub-element in the list is constrained to a particular data type by the base type system and is constrained to a particular format by the supplemental type system.
7. The method of claim 5 , wherein the visual feedback comprises an indication that a sub-element in the list is constrained to a particular data type by the base type system and is constrained to a particular format by the supplemental type system. 8. The method of claim 7 , wherein the particular data type is string.