no idea anyone?

Richtlinie 2006/112/EC, Art. 226 (11):
"...in the case of an exemption or where the customer is liable for payment of VAT, reference to the applicable provision of this Directive, or to the corresponding national provision, or any other reference indicating that the supply of goods or services is exempt or subject to the reverse charge procedure;"
Dieser Verweis ist es, den Du machen sollst, und diese Formulierung ist das Äquivalent zur deutschen von Dir zitierten.

Thanks, great!