Contents

1 General Points

This document describes programming abbreviations. Abbreviations are quite general: Any shortened form of a word, phrase, or concept is an abbreviation. Hence, abbreviations can be acronyms, initialisms, or nicknames. Concise abbreviations for variable names are especially important because they help make a program become self-documenting and thus easier to maintain. Consistent abbreviations across programs are important because then whole suites of code can be updated an improved in a more modular fashion. An alternative method of naming variables is the Hungarian notation method originated by Charles Simonyi of Microsoft http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnvsgen/html/hunganotat.asp

1.1 Abbreviations

Abbreviations are usually used for variable names in a program. Naming a variable appropriately often speeds up programming by reducing the introduction of bugs to the program, and by making future maintenance easier. An effective abbreviation has a number of desirable qualities.

• Concise
• Unambiguous
• Easy to remember
• Distinct from English

Here are some guidelines which help in creating abbreviations with these qualities:

1. A common acronym, if it exists, is preferable to creating a new abbreviation (e.g., SWCF).
2. Abbreviations which do not contain common letter combinations of the English language are much easier to program. Searching and replacing uncommon letter combinations lessens the risk of corrupting plain text and comments in the program. For example, using flx rather than flux saves only one letter, but makes code maintenance much easier.
3. Phonetic abbreviations are often superior mnemonics. Use, e.g.,nvr rather than env for “environment”. Phonetic abbreviations make it easier to use consonants, which are better than vowels in abbreviations.
4. All things being equal, three letter abbreviations, or groups of them, are best. Three letters are easy to remember yet there are enough permutations to abbreviate almost atomic concept into a three letter abbreviation.
5. Single letter abbreviations, e.g. “t = temperature”, are always a mistake. It is nearly impossible to perform a quick search or search-and-replace on a single letter variable.
6. Sometimes an abbreviation is an acronym but is not capitalized. Capitalize the abbreviation when it is common (e.g., SWCF), but leave it lowercase when it is uncommon (e.g., mpc).

1.2 Variable Names

Use underscores to aggregate abbreviations into longer groups which compose a variable name. Underscores are easier to proofread than the X-style capitalization method, e.g., flx_bb_dwn_sfc vs. FlxBbDwnSfc or FluxBroadbandDownSurface. Variables names constructed in this manner have the desirable property that, when they are alphabetized, related variables are grouped together.

1.3 Definitions

Often an abbreviation is used to keep a quantity distinct from a related but distinct quantity. In these cases the abbreviations are called antonyms. In the list, the antonym of a given definition is indicated by “ant.”. Occasionally an abbreviation has a synonym, too. In the list, the synonyms are indicated by “syn.”.

The abbreviation is followed by the definition. In some cases the definition has multiple related meanings—these are separated by commas, e.g., “abs = absorption, absorbed, absorbing”.

In a few cases, the definition has multiple distinct meanings—these are separated from one another by “or”, e.g., “aer = aerosol, aerosol-laden (turbid), or aerodynamic”.

2 Abbreviations

Abbreviations of financial terms:

Physical units and dimensions:

Consumer electronics

Geographical places, stations, regions, and features: this points to sxn:abb

Initials (often used as change markers in source code):