Bip-39. From this place forward the seed may very well be composed on paper or spoken over telephone which opened up new, physical ways of backing up the seed (multiple paper copies in several destinations, sturdy copies on steel plates with additional defense from fireplace/flood and so forth.). Seed phrases https://socialislife.com/story4024899/bip39-to-bip32-indicators-on-phrases-with-bit-you-should-know