Bip39 Api. From this place forward the seed can be composed on paper or spoken more than telephone and this opened up new, Actual physical ways of backing up the seed (several paper copies in several locations, tough copies on metal plates with excess protection from hearth/flood and so on.). https://financenews81470.wikiconverse.com/5171822/the_anatomy_of_the_bip39_phrase_entropy_words_and_phrases_and_safety