Numbers followed by units of measure should never be written out.
- Bad: It was a one GB hard drive
- Good: It was a 1 GB hard drive
- Example: There were nine cables.
- Example: There were nine cables numbered “1" through “9".
- Example: Go to the menu and select ten or more.
- Example: Thirteen revisions have been created.
- Example: Approximately 1 in 300 modems failed in the first year.
- Example: There were twenty-seven 802.11 abg wireless pc cards in stock.
Units of measurements
Abbreviations of units should not be followed by a period unless they are at the end of a sentence.
Abbreviations of units should be lower case except in the following situations:
Units of measure named for a person should be upper case (e. g. : kHz).
Bytes are abbreviated B, bits b (e. g. : 5 GB hard drive and 1Gb Ethernet.
Metric abbreviations are case-sensitive, so uppercase and lowercase letters have different meanings
- mm stands for millimeter (one-thousandth of a meter)
- Mm stands for megameter (one million meters)
- Good: 100 GB
- Bad: 100 GBs
Units of computer memory
The computer industry commonly refers to:
- A factor of 1024 (2 to the power of 10) as “k"
- 1024 squared (2 to the power of 20) as “M"
- 1024 cubed (2 to the power of 10) as “G"
- k that stands for kilo and means thousand (1,000 or 10 to the power of
- M that stands for mega and means million (1,000,000 or 10 to the power
- G that stands for giga and means billion (1,000,000,000 or 10 to the power
There should always be one blank space between a number and a unit (preferably a non-breaking space)
Whenever possible, give numerical values in comparisons and explanations to avoid ambiguity:
- Bad: Older hard drives were smaller.
- Better: Hard drives manufactured before 1999 had less than 1 GB of storage
- Bad: The 5400 rpm hard drive is faster than the 100 GB hard drive.
- Better: The 5400 rpm 50 GB hard drive performed better in the seek test
than the 2700 rpm 100 GB hard drive.
- Not so good: To compare and contrast the performance of this process on
an idle system with 256 MB, 512 MB and 1 GB of RAM. . .
- Better: To compare and contrast the performance of this process on an idle
system with 256 MB, 512 MB and 1024 MB of RAM. . .
- Exception: if the measurement remains the same and the unit changes, it
can be used for emphasis (e. g. it costs $10 per year where it used to cost
about $10 per month)
Use the dd Mon yyyy format because it is less ambiguous, and globaly recognizable.
- Example: 08 Jun 2006
- HTML: Hyper text markup language
- PC: Personal computer
- (ADD TO THIS LIST)
- Example: Three letter acronyms (TLAs) are abundant in technical writing.
Torre DeVito is a computer programmer, technical writer, and web designer from North Carolina. He is the proprietor of PageCandy.com and GraphicalSiteFX.com.