Bip39 Mnemonic. The passphrase is just not chosen within the predefined list of 2048 words – it may be any word or phrase you select. What constitutes a "very good wallet" is one that has crystal clear, easy to entry documentation on supported BIP standards, derivation paths, and Restoration processes. https://bookmark-dofollow.com/story23583625/bip39-wallet-https-linktr-ee-bip39-the-basic-principles-of-bip39-mnemonic