Bip39 Validate Mnemonic. From this level forward the seed can be prepared on paper or spoken more than phone and this opened up new, Actual physical ways of backing up the seed (a number of paper copies in different locations, strong copies on steel plates with additional defense from hearth/flood https://socialevity.com/story20407626/bip39-word-checker-the-fact-about-seed-phrase-generator-and-checker-that-no-one-is-suggesting