Solution : https://service.sap.com/sap/support/notes/1045736 (SAP Service marketplace login required)
Key words : 
terms material master integrationmaterial - substance - assignmentmaterial - specification - assignment reason, user/material type/transaction/industry sector, logistics general -> material master -> configuring, record xxx xxx xxx, matl type roh sref, assign material type roh, material type screen reference, assign screen sequence sp, matl type roh, material type roh
Related Notes : 
       
| 1287816 | Identifiers for material master integration | 
| 959311 | Advanced search for specification input help | 
| 943485 | Navigating to specification material assignment | 
| 816806 | SAP ECC 5.0 Enterprise Extensions: Activation switch | 
| 666925 | SAP R/3 Enterprise Extension Set 200: Activation switch | 
| 535003 | SAP R/3 Enterprise Extension Set 1.10: Activation switch | 
| 108059 | Transport of Customizing settings made in OMT3 |