Solution : https://service.sap.com/sap/support/notes/74055 (SAP Service marketplace login required)
Key words : 
terms component supply processing, changing abap dictionary objects, customer-specific variable messages, customer-specific messages, message version reason, higher release levels, extras --> maintenance status, maintenance status back, abap dictionary, release levels 3
Related Notes : 
       
| 965146 | Version ignored in variable messages | 
| 370443 | SD document blocked: No billing-relevance (third-party) | 
| 356272 | No note on production orders with rejections | 
| 351365 | SD EDI ORDCHG: Item is not deleted | 
| 334501 | Delivery groups with different shipping points | 
| 206452 | Quantity change in ordered third-party order | 
| 204190 | Third-party: No update of purchase order with SP change | 
| 182959 | Valuation data for material is missing | 
| 182015 | Message V4156 cannot be maintained | 
| 179012 | Incor. requments. w. negative quantity in transit | 
| 171646 | Returns with not existing batch - message | 
| 145022 | Proposed cumulative quant. received:message missing | 
| 125736 | Negative cumul. received qty in delivery sched. | 
| 121728 | Open qty/requirements for sched.agreemts different | 
| 103559 | 'Item proposal': No note on quotations/contracts | 
| 97986 | Variable message V4155 is missing | 
| 89666 | Pick-up date can be changed with no warning msg | 
| 88713 | Some variable messages cannot be customized | 
| 71092 | Deliv. scheds.: Messages despite compl.scheduling |