Mnemonic

Overview
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.

The word mnemonic is derived from the Ancient Greek word μνημονικός mnemonikos ("of memory") and is related to Mnemosyne ("remembrance"), the name of the Mother of the Muses in Greek mythology. Both of these words refer back to μνημα mnema ("remembrance"). The first known reference to mnemonics is the method of loci described in Cicero's De Oratore.

Key-word mnemonics
Visual mnemonics are very popular in medicine as well as other fields. In this technique, an image portrays characters or objects whose name sounds like the item that has to be memorized. This object then interacts with other similarly portrayed objects that in turn represent associated information. Mnemonic techniques can also be strategies for encoding information so that recall is easier. A good example of medical visual mnemonics Mediglyphics Pharmacology

Acronym and acrostic mnemonics
One common mnemonic for remembering lists consists of an easily remembered word, phrase, or rhyme whose first letters are associated with the list items. The idea lends itself well to memorizing hard-to-break passwords as well. Though easy to derive, they are often not as powerful as the classical systems because they do not make use of visualization techniques.

Anamonics (Scrabble)
Many tournament Scrabble players employ anamonics, a form of initialization mnemonic, for the purposes of learning and quickly recalling sets of acceptable words. An anamonic consists of a "stem" (usually of six or seven letters), paired with a semantically related phrase, in which each letter of the phrase can be added to the stem and rearranged to form at least one acceptable word. For example, if a player has the tiles "ACDEIRT" on his rack, and recalls the anamonic "DICE-ART = casino math diploma", they will know precisely which letters may be played through to form 8-letter words, and will hopefully be aided in finding the words: "ACCREDIT", "RADICATE", "ACRIDEST", "RATICIDE", "DICENTRA", "CERATOID", "TIMECARD", "CITRATED"/ "TETRACID"/ "TETRADIC", "TRACHEID", "READDICT", "PICRATED", and "ARTICLED"/ "LACERTID".

Other mnemonic systems

 * Mnemonic major system
 * Mnemonic dominic system
 * Mnemonic link system|Link System
 * Mnemonic peg system
 * Mnemonic goroawase system|Goroawase System
 * Mnemonic journey method|Journey method
 * Method of loci
 * Latin mnemonics|Mnemonics for Latin study

Arbitrariness of mnemonics
A curious characteristic of many memory systems is that mnemonics work despite being (or possibly because of being) illogical, arbitrary, and artistically flawed. A commonly effective mnemonic for remembering the color sequence in a rainbow, "Roy G. Biv", is a combination of such unlikely elements: "Roy" is a legitimate first name, but there is no actual surname "Biv" and of course the middle initial "G" is arbitrary. Medical students never forget the arbitrary nationalities of the Finn and German. Any two of the three months ending in -ember would fit just as euphoniously as September and November in "Thirty days hath...", yet most people can remember the rhyme correctly for a lifetime after having heard it once, and are never troubled by doubts as to which two of the -ember months have thirty days. Associations which are exaggerated, absurd, humorous or have sexual connotation are easier to remember than normal ones.

One reason for the effectiveness of seemingly arbitrary mnemonics is the grouping of information to reduce cognitive load. Just as US phone numbers chunks 10 digits into three groups, the name "Roy G. Biv" chunks seven colors into two short names and an initial. Various studies (most notably Miller's The Magical Number Seven, Plus or Minus Two) have shown that the human brain is capable of remembering only a limited number of arbitrary items; chunking these items permits the brain to hold more of them in memory.

Assembly mnemonics
In assembly language a mnemonic is a code, usually from 1 to 5 letters, that represents an opcode, a number.

Programming in machine code, by supplying the computer with the numbers of the operations it must perform, can be quite a burden, because for every operation the corresponding number must be looked up or remembered. Looking up all numbers takes a lot of time, and mis-remembering a number may introduce computer bugs.

Therefore a set of mnemonics was devised. Each number was represented by an alphabetic code. So instead of entering the number corresponding to addition to add two numbers one can enter "add".

Although mnemonics differ between different CPU designs some are common, for instance: "sub" (subtract), "div" (divide), "add" (add) and "mul" (multiply).

This type of mnemonic is different from the ones listed above in that instead of a way to make remembering numbers easier, it is a way to make remembering numbers unnecessary (by relying on some external way to tie each mnemonic to a number).

Los Angeles, California, Downtown Streets Mnemonic
Central downtown Los Angeles can be a confusing maze, both for "suburbians" and tourists alike. Moving from North to South (actually NE to SW), it's fairly easy to go from the 101 (Hollywood/Santa Ana) Freeway to Temple Street, followed by Tom Bradley Blvd. (previously 1st Street), then 2nd Street, 3rd Street, etc. However, East to West (actually SE to NW) is a bit more challenging to navigate. At some point, someone introduced a mnemonic sentence to recall the order of the 10 primary East to West streets. This version is courtesy of St. Louis, Missouri, native Helen Anshutz Meixsell, who began her residency in Los Angeles in 1927 at the age of nine. It was taught to her by her aunt, MayBelle Anshutz, who had been in California since 1926. After Ms. Meixsell's graduation from Los Angeles High School in 1936, and until 1942, she worked at various jobs from downtown Los Angeles to her non-enlisted WWII military job at Douglas Aircraft across town in Santa Monica. Although slight variations can undoubtedly be found, Ms. Meixsell memorized it this way in 1935 in anticipation of traveling to work: In LOS ANGELES, you MAINly SPRING onto BROADWAY, go up the HILL to OLIVE with the GRAND HOPE of picking FLOWERs on FIGUEROA. (All roads mentioned in the saying are "streets" except for Grand, which is an "avenue".) She utilized the expression every day as she regularly walked, took city buses and rode the “Red Car” to her jobs.

UK Fuel Mnemonics
All UK petrol (gasoline) stations use a Mnemonic code to identify themselves. This remains the same no matter how many times the service station changes hands. These are made up of seven letters. The first three letters are the site name. The next set of three are the name of the town the site is located in or near. The seventh letter is always an R. For example, a site named Rock in Stamford, Lincolnshire|Stamford has the mnemonic ROCSTAR. Occasionally an extra letter is added if there are, or once were, two sites with the same name on either side of a motorway or trunk road. As the sites are usually appended South or North, depending on which side of the road they are, this letter is added either between the 3rd and 4th letter or before the final R. So a site called Orsett North near Ockendon becomes ORSNOCKR or ORSOCKNR, and Orsett South is ORSSOCKR or ORSOCKSR.