Solution : https://service.sap.com/sap/support/notes/102039 (SAP Service marketplace login required)
Key words : 
3-tier systems                  ii   release 3, install 3-tier systems, installing 3-tier systems, /400 3-tier reason, 3-tier installation, terms installation, prerequisites information, /3 installation, installing, information
Related Notes : 
       
| 484548 | iSeries: 3 tier system installation | 
| 97816 | INST: 3.1I R/3 Installation on IBM AS/400 | 
| 70932 | INST: AS/400 post-installation/upgrade steps 3.1G | 
| 43180 | Missing authorizations from 3.0E |