[Interoperability] The ISO 20022 standard does not render any existing blockchains invalid. This standard specifies the structure of messages between financial institutions, not which technologies can or cannot process payments. Legacy systems can be made compatible by using message transformation tools or middleware. Blockchains that support data mapping or interoperability can still participate in ISO-standard-based financial messaging. The key difference lies in integration capabilities, not the age or version of the blockchain.