Solution : https://service.sap.com/sap/support/notes/84324 (SAP Service marketplace login required)
Key words : 
apply hot package sapkh31g11, user-defined data types, data type udef, additional key words, individual components, solution correct, indicator atcod, recognized, prerequisites, characteristics
Related Notes : 
       
| 91440 | Rel.3.1I: F1-help for UDEF characteristics | 
| 83982 | 3.1I: Check table and function for UDEF data type |