This paper provides an overview of the compliance scheme put forward in this regulation, and what national variations are to be expected, based on the implementations seen in selection of member countries. It also provides an outlook on further harmonization and standardization efforts being made. Finally, the paper suggests an approach for how in practice to provide proof of compliance for a collection of different countries in a proactive and efficient way to ensure a wide market acceptance, which can later also be extended to other grid codes or changing requirements.