Bip39 Checksum. You should then do a essential recovery using a command similar to the one beneath. (This command uses a sample wallet file bunlded with BTCRecover) What constitutes a "very good wallet" is one that has clear, simple to entry documentation on supported BIP requirements, derivation paths, and Restoration https://sociallytraffic.com/story4034251/bip39-https-linktr-ee-bip39-not-known-factual-statements-about-bip39-list