Block top - The block range and duration of your blockchain (in blocks) on generation of the present block Nonce - The transaction number for your 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://bookmarkswing.com/story22078527/a-review-of-blockchain-explorer-xrp-https-diigo-com-010nvri