Here you set the compensation invoice mapping for myDATA.
When you issue a compensation invoice and need the combination shown in the EMDI screenshot.
Open Settings → Tax connections → Variable mapping and fill the yellow myDATA fields on the related document / VAT. The basics are in the main myDATA mapping article.
On-screen steps
What the codes mean
Often related to other/unusual income or out-of-scope acts (exemption reason 1). Do not copy blindly; match the screenshot and ask your accountant if unsure.