EMA C++ RDM Usage Guide : 5 Dictionary Domain : 5.2 Decoding Field List Contents with Field and Enumerated Types Dictionaries
 
5.2 Decoding Field List Contents with Field and Enumerated Types Dictionaries
By itself, a FieldEntry contains only the FieldId and its associated encoded value in Data. Because the Enterprise Message API internally stores pre-decoded data, an application can easily decode a FieldEntry (without cross-referencing the FieldId to the correct Field Dictionary to determine its type).
Figure 9. FieldList Referencing Field Dictionary
If the field’s type is DataTypeEnum::EnumEnum, there may be a table of values in the corresponding Enumerated Types Dictionary. The consumer can then reference that information.
 
Figure 10. FieldEntry Referencing an Enumerated Types Table
The consumer, having decoded the enumerated value (e.g., 840), finds the correct table that defines the field and looks up the enumerated value in that table. The value will have a displayable string associated with it (e.g., USD).