Bip39 Compliant. From this issue forward the seed can be prepared on paper or spoken above phone and this opened up new, Bodily means of backing up the seed (a number of paper copies in various areas, durable copies on metal plates with extra protection from fire/flood and so forth.). https://zandernyjue.mysticwiki.com/1101304/the_anatomy_of_a_bip39_phrase_entropy_words_and_stability