Solution : https://service.sap.com/sap/support/notes/386419 (SAP Service marketplace login required)
Key words : 
additional key words confirmation, conversion exit conversion_exit_matn1_input processes, field 'storage location', online dump dynpro_msg_in_help, reduced material number, entered material number, material number, confirmation transactions, material overview, goods movement
Related Notes : 
       
| 389975 | |
| 331007 | Input help for storage location: Dump DYNPRO_MSG_IN_HELP |