Bip39 Docs. From this point ahead the seed might be penned on paper or spoken about telephone which opened up new, physical ways of backing up the seed (various paper copies in several areas, strong copies on steel plates with more safety from fireplace/flood and so on.). You signed in https://finance-auto-now82615.blgwiki.com/1105294/the_anatomy_of_a_bip39_phrase_entropy_phrases_and_security