Memo or tag
In short: Additional payment information used by a protocol feature or recipient to identify or accept a transfer.
Additional payment information used by a protocol feature or recipient to identify or accept a transfer. A network name alone does not establish whether it is required. Follow the destination's exact receiving instructions. If additional information is required, confirm that the sending interface carries it in the right form. A personal note or message field may not serve the same purpose, and omitting a required identifier can prevent normal crediting.