Block top - The block selection and length with 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://socialstrategie.com/story6210070/how-blockchain-explorer-xrp-can-save-you-time-stress-and-money-https-www-instapaper-com-p-16864836