Block top - The block amount and size on the blockchain (in blocks) on generation of the present block Nonce - The transaction number for the from address (bear in mind this starts at 0 so a nonce of 100 would really be the 101st transaction submitted by this account) https://atozbookmark.com/story20173089/blockchain-explorer-usdt-trc20-fundamentals-explained-https-www-instapaper-com-p-16864836