Bip39 Standard. The passphrase will not be chosen from the predefined list of 2048 words – it can be any word or phrase you select. Any person else who discovers the phrase can steal the bitcoins. It must be held top secret, for instance it have to not be typed https://bookmarkedblog.com/story20388643/bip39-https-linktr-ee-bip39-bip39-words-fundamentals-explained