Acronym it. This has become such a problem that it is even evaluated at the level of medical academies such as the American Academy of Dermatology. Acronyms are often taught as mnemonic devices, for example in physics the colors of the visible spectrum are said to be "ROY G. BIV" ("red-orange-yellow-green-blue-indigo-violet"). They are also used as mental checklists, for example in aviation: "GUMPS", which is "Gas-Undercarriage-Mixture-Propeller-Seatbelts". Other examples of mnemonic acronyms are "CAN SLIM", and "PAVPANIC" as well as "PEMDAS". It is not uncommon for acronyms to be cited in a kind of false etymology, called a "folk etymology", for a
QNH modulated radio was often difficult to receive, and communication was done by Morse Code. To avoid the need for long Morse transmissions, many of the most commonly used communications were incorporated into a Q code. To ask for atmospheric pressure at sea-level (i.e., at zero altitude) the letters 'QNH' would be transmitted. A common mnemonic for QNH is "Query: Nautical Height". Student pilots may sometimes remember QNH as "Query: Newlyn Harbour". Newlyn Harbour in Cornwall, UK is home to the National Tidal and Sea Level Facility, which is a reference for mean sea level. Another way to remember is "Query: