An 18-word mnemonic phrase increases security by adding further words on the sequence. Here’s an example: Standard recovery phrases use a particular list of 2048 words following the BIP39 standard (Bitcoin Improvement Proposal 39). You are able to verify If the words are part of the BIP39 list applying these https://thebookmarkage.com/story18796894/the-basic-principles-of-bip39-passphrase-generator