API release: Sales price tables

The tables 'Debtor Discount Groups', 'Discount p. debt.disc.grp. / item.disc.grp.', 'Discount per Debtor / Item Discount Group', 'Discount Packages', and 'Discount Package Lines' have been released for the MKG API. It is possible to perform GET, PUT, POST, and DEL calls here. More information about the calls can be found in the Data Dictionary: tables respectively 'dekg', 'dgag', 'deag', 'vokp', and 'vokr'.