Bip39 Tool. The passphrase is just not picked from the predefined list of 2048 words – it may be any word or phrase you select. BIP39 specifies a list of 2048 words from which the mnemonic phrase is selected. Just about every word signifies a range in a binary sequence, https://bookmarkfriend.com/story19525259/bip-39-https-linktr-ee-bip39-an-unbiased-view-of-bip-39