Here you set documents with VAT reverse charge (Article 45 of the new VAT Code / former 39a).
Use this when the customer accounts for VAT (e.g. recyclables, emission allowances, mobiles/tablets/laptops, etc.).
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
The myDATA VAT exemption reason is code 16 (without VAT – Article 45 / former 39a). Do not confuse it with code 22 (VAT included in a different case). See also the VAT exemption reasons article.