Solution : https://service.sap.com/sap/support/notes/1022091 (SAP Service marketplace login required)
Key words : 
tax-exempt intra-community delivery, ers credit memo, credit memo recipient, attached correction instructions, acquisition tax, invoice posted, terms tax1, reverse batch, spc reason, legal change
Related Notes : 
       
| 1513462 | MR90: Tax Code with EU indicator (VAT 2010) part 2 | 
| 1483661 | MR90: Tax Code with EU indicator (VAT 2010) | 
| 1409415 | KONS/KON6: Tax codes with EU indicator | 
| 1392962 | Acquisition tax condition display in Purchase order | 
| 778477 | MR90: EU directive on tax exemption |