ERC-721 (NFT Standard)

ERC-721 is the Ethereum standard for non-fungible tokens (NFTs). It defines a common interface — ownership, transfer, approval — that wallets, marketplaces, and other contracts can rely on. Because tokenized domains are typically implemented as ERC-721 NFTs, they get instant compatibility with the broader NFT ecosystem: OpenSea, Blur, and similar marketplaces can list them; standard wallets like MetaMask, Rabby, and hardware wallets can hold them; NFT-aware lending and rental protocols can plug into them. There is also a related batch standard, ERC-1155, used for fungible/semi-fungible tokens — domains are not usually issued under ERC-1155 because each domain is unique. Reference: EIP-721 specification.