Block top - The block selection and length from the blockchain (in blocks) on creation of the current block Nonce - The transaction variety for that from address (Remember this starts off at 0 so a nonce of a hundred would actually be the 101st transaction submitted by this account) https://bookmarkfox.com/story6133960/what-does-blockchain-explorer-usdt-mean-https-squareblogs-net-heartgarlic3-delving-into-blockchain-explorers