According to the Oxford online dictionary a Mnemonic (/nɪˈmɒnɪk/) is ‘a system such as a pattern of letters, ideas, or associations which assists in remembering something’.
As the definition outlines mnemonics are a good way to remember ideas. In this case, the persuasive writing mnemonic is great to use as a guide to remember all the things that should be included in your persuasive essays.