Solution : https://service.sap.com/sap/support/notes/1007341 (SAP Service marketplace login required)
Key words : 
ep nw04s business packages ess, ep nw04 business package mss, sap erp 2005 system landscapes listed, business packages ess sap erp 2004, business packages ess sap erp 2005, erp 2004 back-end system, erp 2005 back-end system, terms ess system landscape, nw04 business package mss, sap erp 2004 system landscape
Related Notes : 
       
| 1303362 | ESS/MSS and Enhancement Packages | 
| 1245560 | Composite SAP Note : XSS Documentation | 
| 1034385 | BP ESS/MSS ERP2004 and ERP2005 on EPNW04s | 
| 1032311 | Display HTLM Trip form in place of PDF form in ERP 2005 | 
| 1030552 | BP ESS 60.2 (ERP 2004) Travel with ECC 600 (SAP ERP 2005) | 
| 978773 | Information: BP ESS/MSS ERP2004 on EP6.0 against XSS 600/ECC | 
| 966083 | Web: Exit button does not work when coming from 'My Alerts' | 
| 965365 | ERP2005 ESS applications in combination with 2004 BP | 
| 953254 | Transfer of ERP processes (HCM) into new functions | 
| 952693 | MSS: Interactive forms and HCM processes and forms | 
| 952692 | Transfer of SAP MSS functions to mySAP ERP 2005 | 
| 905135 | ITS 6.20 logon to system with 7.0 kernel not possible | 
| 903319 | Composite note: MSS ERP 2005 (Human Resources Management) | 
| 879335 | Additional information about Self Service Upgrade | 
| 870126 | ITS-based ESS services in SAP ERP2005 | 
| 771196 | ESS: ITS conversion PV7I and PV8I | 
| 755088 | Composite SAP note: Manager Self-Service ERP 2004 (my team) | 
| 709038 | SAP Integrated ITS |