Mnemonic

adj. of or designed to assist the memory

n. something that is designed to assist the memory (often referring to a word or group of words that can be associated with the information being remembered)

A mnemonic (pronounced in RP, in GA) is a memory aid that generally serves an educational purpose. They are mostly verbal, e.g a word, each of whose letters help the user to remember the first letters of items in a list. However, there are also other types of mnemonics, such as visual mnemonics. Mnemonics rely on associations between something that is easy to remember, and something that is harder to remember. Sometimes mnemonics are chosen to directly relate to the target information, and othertimes they are arbitrary.
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(a.)
Alt. of Mnemonical
  

<programming> A word or string which is intended to be easier to remember than the thing it stands for. Most often used in "instruction mnemonic" which are so called because they are easier to remember than the binary patterns they stand for. Non-printing ASCII characters also have mnemonics like NAK, ESC, DEL intended to evoke their meaning on certain systems.
(1995-05-11)

any memory aid; in marketing we use acronyms and models.