Solution : https://service.sap.com/sap/support/notes/123323 (SAP Service marketplace login required)
Key words :
additional key words mailing action, direct mailing campaign parameters, billing document, text symbols, text_symbol_replace, mailaktionsparameter, prerequisites
Related Notes :
| 81687 | Billing document printout - collective note |
| 49174 | NAST: VF01 Replacement of symbols does not work |