4. Certified units shall be issued by certification registries or, once established, by the Union registry only after the generation of a net carbon removal benefit or net soil emission reduction benefit, based on a valid certificate of compliance resulting from a re-certification audit.
Any certified unit shall not be issued more than once and shall not be used by more than one natural or legal person at any point in time.
Permanent carbon removal units, carbon farming sequestration units, carbon storage in product units and soil emission reduction units shall remain distinct from one another.