(4)Crypto-assets that are not financial instruments cannot at present be described by using the ISO Classification of Financial Instruments (CFI) code. A standard universal method of classification is being developed. However, this method of classification will not be finalised before the application of this Regulation. Hence, to identify the crypto-asset white papers consistently in the register referred to in Article 109(1) of Regulation (EU) 2023/1114, an international standard identifier for digital tokens, the Functionally Fungible Group Digital Token Identifier (FFG DTI) should be used. Furthermore, to identify the crypto-assets and to allow users to retrieve the main characteristics of the crypto-assets, including their technology-specific features, and to group tokens issued on several blockchains that are pertaining to the same crypto-asset white paper, the ISO 24165 Digital Token Identifiers (DTI) should be used. The FFG DTI and the DTI are appropriate for the purposes of the register since they respect the principles of uniqueness, neutrality, reliability, open source, scalability, accessibility on a cost-recovery basis and they are offered under an appropriate governance framework.