Non-Transferable Tokens
The XRP Ledger supports non-transferable tokens (NTTs), sometimes called soulbound tokens, as a specific class of non-fungible tokens. Non-transferable tokens may be used for certifications and identity tokens, achievements in games, or other cases where the purpose of the token is limited to one person specifically.
Any NFT in the XRP Ledger that has the Transferable flag disabled is a non-transferable token. This flag is set when the NFT is minted using the tfTransferable
flag of the NFTokenMint transaction. After the NFT is created, the transferable status is recorded as the lsfTransferable
flag of the NFToken object.
Non-transferable tokens can still be transferred to or from the issuer of the token directly, but users cannot transfer the token among themselves.