1.   Crypto-asset service provider operating a trading platform for crypto-assets shall identify natural persons in the order book records by using the designation resulting from the concatenation of the ISO 3166-1 alpha-2 specified in ISO 3166 followed by the national client identifier as specified in Annex II of Delegated Regulation (EU) 2017/590 based on the nationality of the person. The two-letter country code shall correspond to the nationality of natural person.

2.   The national client identifier referred to in paragraph 1 shall be assigned in accordance with the priority levels provided in Annex II of Delegated Regulation (EU) 2017/590 using the highest priority identifier that a person has regardless of whether that identifier is already known to the crypto-asset service provider operating a trading platform for crypto-assets.

3.   Where a natural person is a national of more than one European Economic Area (EEA) country, the country code of the first nationality when sorted alphabetically by its ISO 3166-1 alpha-2 code and the identifier of that nationality assigned in accordance with paragraph 2 shall be used. Where a natural person has a non-EEA nationality, the highest priority identifier in accordance with the field referring to ‘all other countries’ provided in Annex II of Delegated Regulation (EU) 2017/590 shall be used. Where a natural person has an EEA and a non-EEA nationality, the country code of the EEA nationality and the highest priority identifier of that nationality assigned in accordance with paragraph 2 shall be used.

4.   Where a natural person is a resident of a country other than the one of its nationality, crypto-asset service providers operating a trading platform for crypto-assets shall also identify that natural person based on the country of its residence as specified in field 50 of Table 2 of the Annex.

5.   Prefixes to names shall be excluded and first names and surnames shorter than five characters shall be appended by ‘#’. All characters shall be in upper case. No apostrophes, accents, hyphens, punctuation marks or spaces shall be used.

6.   Where the identifier assigned in accordance with paragraph 2 is based on CONCAT, the natural person shall be identified by the crypto-asset service provider operating a trading platform for crypto-assets using the concatenation of the following elements in the following order: