Solution : https://service.sap.com/sap/support/notes/217231 (SAP Service marketplace login required)
Key words : 
additional key words mass maintenance, purchasing info record, functional group eimass, attached program correction, mass maintenance, transaction mass, purchase requisition, purchase order, function modules, descriptions ekko
Related Notes : 
       
| 1449703 | PO Mass maintainence should not show OIL fields. | 
| 417067 | |
| 397391 | |
| 325947 | Change purchase requisitn from batch input to BAPI |