Bip39. First of all you need to retail outlet it SEPARATELY from the seed. Acquiring your seed plus your passphrase in precisely the same site defeats the purpose of possessing a passphrase to begin with. No, there is no technical limit for the duration of one's passphrase. Having said that, https://crossbookmark.com/story18654815/bip39-https-linktr-ee-bip39-bip39-word-list-pdf-no-further-a-mystery