Solution : https://service.sap.com/sap/support/notes/896144 (SAP Service marketplace login required)
Key words : 
multiple processing code pages system - system running, sap erp-mdmp - back ends, mdmp means multiple display, standard code pages, blended code page, symptom sap erp 6, mdmp sap erp 6, contact globalization@sap, windows + abap existing, ess/mss - scenarios
Related Notes : 
       
| 1431088 | Globalization FAQs | 
| 1319517 | Unicode Collection Note | 
| 938738 | Syslog CP6: still using ambiguous blended code page | 
| 938737 | Syslog CP6: still using blended code page | 
| 852235 | Release Restrictions for SAP ERP 6.0 | 
| 747036 | mySAP ERP 2004 Upgrade for R/3 MDMP Customers | 
| 548016 | Conversion to Unicode | 
| 79991 | Multi-Language and Unicode support of SAP applications |