arpadveress 
You must prove you have it. It means you purchased it. There is an invoice. Another option: online access. One of the 2.
Any Ex site compliance audit / inspection / engineering / operation / repair work shall pay attention to this topic. Same goes for installation and design.
Otherwise the legal basis of Ex is missing.
Copy paste and share of standards do not work here. Immediate non compliance.
Keep up good work.
Arpad
