Mnemonics may be useful to the crafting of coding structures, but only structures that are likely to make sense over longer periods of time. Mnemonic devices can be employed to help people remember or interpret something, like a string of letters. It is a memory technique to help your brain better encode and recall important information.
One application where I have seen this used is in the formulation of organisation codes or cost centres. Imagine you have a business division called the Consumer Goods Division with eight operating regions, two in each of Wellington and Auckland, and one each in Christchurch, Whangerei, Rotorua and Invercargill, with a divisional head office based in Auckland. Each operating Region has a General Manager, a Financial Controller, a Sales Manager and an Operations Manager. How might these be represented as organisation codes? First we need a set of business rules:
1) A useful content rule to avoid misinterpretation is to exclude the use of the letters O, I, and S on the basis that these can be confused with zero, one, and five respectively.
2) An organisation code might be limited to say six alphanumeric characters.
3) Each of the first three character positions is reserved for an alphabetic character with the first being the division identifier (let us use “C” for Consumer Division), the second the region identifier and the third is the functional area.
4) The remaining three characters are simply sequential numeric.
From these, we would derive the following organisation codes:
Wellington North CWG001 (where “W” is the first instance in Wellington)
CWF001 (Where “F” is for Finance)
CWS001 (Where “S” is for Sales)
CWP001 (Where “P” is for OPerations)
Wellington South CNG001 (where “N” is the other end of Wellington)
… and so forth.
It helps if each of the locations has a unique starting and ending letter, but you are usually stuck with place names, so some variations will apply. In the example, given the business rules, Invercargill has five problematic letters, so the region identifier would probably best be “V”. Whangerei also presents five problematic characters. This includes “H” which could be misinterpreted as “Head Office”, so the region identifier in this case would probably be “G”. Rotorua should be able to be identified with an “R”, and Christchurch should have a “C” identifier, in spite of containing seven problematic letters.
We would therefore arrive at the following list:
Wellington North - CW….
WellingtoN South - CN….
Auckland East - CA….
AucklanD West - CD….
Christchurch - CC….
WhanGerei - CG….
Rotorua - CR….
InVercargill - CV….
Head Office - CH….
Say the Division identifier equals “C” for the Consumer Goods Division and the Region equals "A" for Auckland North. If the Division is merged with the Products Division and is renamed the “Products & Innovation Division”, the Division identifier “C” as a mnemonic device becomes meaningless. Similarly if Auckland North and the other regions in the north of the country become “North Island Region” the “A” becomes meaningless as a mnemonic device. So if there was no re-organisations and/or renaming, then mnemonics helps with interpretation, but in the reverse situation mnemonics do not help memory or interpretation at all.
Of course, there could be problems with poorly formed Cs being mixed up with Gs and vice versa. I don’t know about you, but, about here, my head hurts. It illustrates though, that the more unique the place names, the easier the logic to remember. Now I won’t be cruel and introduce the effect of re-organisations, but does this actually make codes easier to interpret than something less structured?