The Ethereum improvement proposal EIP-6147 proposed by 10K Universe has been moved to the final version (Final). This standard is an extension of ERC-721 and separates the holding and transfer rights of NFT and soul-bound tokens (SBT). And a new role is defined, namely guard (expiration time can be set). The flexibility of guard settings makes NFT anti-theft, NFT lending, NFT leasing, SBT and other designs possible.​