Bip39n Code. From this position forward the seed could be composed on paper or spoken about phone which opened up new, physical ways of backing up the seed (a number of paper copies in different locations, long lasting copies on steel plates with excess security from hearth/flood and so on.). https://travialist.com/story8796279/bip39-add-private-key-bip39-standalone-can-be-fun-for-anyone