Valid Bip39 Seed Phrase. From this point forward the seed can be created on paper or spoken around telephone and this opened up new, physical means of backing up the seed (a number of paper copies in several destinations, tough copies on metallic plates with excess security from fire/flood etcetera.). https://financeuk36925.wikiusnews.com/1120224/the_anatomy_of_a_bip39_phrase_entropy_terms_and_security