Solution : https://service.sap.com/sap/support/notes/75825 (SAP Service marketplace login required)
Key words : 
'install/codepage/appl_server' profile parameters, 'install/codepage/db/transp', 'install/codepage/db/non_transp', newer patch versions, rscp0020 tools report, database saves bytes, characters remain intact, character sets similar, spanish special characters, character set required
Related Notes : 
       
| 85363 | Database Scan Tool for basis release < 6.20 | 
| 81663 | Hungarian used incorrectly up to now | 
| 45790 | Change English (and German) in table TCP0C | 
| 45619 | R/3 with several languages or several fonts | 
| 42305 | RSCPINST (I18N configuration tool) | 
| 15023 | Initializing table TCPDB (RSCP0004) (EBCDIC) |