Cover Page ofThe Mayfield Handbook of Technical & Scientific Writing
Table of ContentsWriting TimelineHelpCredits

Section 8.3


Use colons for the following purposes:

To set off and emphasize lists

The market for photovoltaic power systems includes the following items:intrusion alarms, flood monitors, calculators, and telephone call boxes.


The market for photovoltaic power systems includes the following items:
  • intrusion alarms
  • flood monitors
  • calculators
  • telephone call boxes

Anyone communicating via computer needs a security system that ensuresthree essential requirements: confidentiality, authentication, and trust.


Anyone communicating via computer needs a security system that ensuresthree essential requirements:
  • confidentiality
  • authentication
  • trust

(Begin each element of lists, series, or phrases with lowercase letters.)

To set off and emphasize quotations

The contract reads: "DL-400 coaxial cable shall be used for all platforminstrument installations at Site 5, unless a specific exception is justified inthe approved work order."

Kulik noted: "Even potatoes are probably much better guarded today thanradioactive materials."

--Phil Williams, and Paul N. Woessner, "The Real Threat of Nuclear Smuggling,"Scientific American

(Place colons outside quotation marks.)

To set off and emphasize explanations andappositional elements

In designing the tachometer, the team first posed a question: Whatoperations are needed on the input signal in order to generate the desiredoutput?

The projects have, however, been able to measure the effects of caloricrestriction on so-called biomarkers of aging: attributes that generally changewith age and may help predict the future span of health or life.

--Richard Weindruch, "Caloric Restriction and Aging,"Scientific American

This system currently operates in a strictly one-sided fashion: the machinemakes sure the person who inserted the card is its legitimate owner by asking fora secret password, but the cardholder must blindly trust that the machine has notbeen tampered with.

While thinking about this problem, we were reminded of an access-controlsystem with similar demands that is used successfully worldwide on a daily basis:passports.

--Thomas Beth, "Confidential Communication on the Internet," ScientificAmerican

To express ratios

The ratio of drag torque to bearing friction torque cannot exceed3:1.

The anti-GAP 43, anti-MAP 2, and anti-synaptophysin antibodies were diluted1:1000, 1:300, and 1:100, respectively, in phosphate-buffered saline containing10% bovine serum albumin.

--Andreas Schwarz et al., "A Regulatory Role for Sphingolipids inNeuronal Growth," Journal of Chemical Biology

To separate units of time

The main thruster engines ignited at at 7:05 a.m. EDT.

Thu Mar 16 03:21:44 1995

To separate elements in a citation (in certaindocumentation styles)

E. F. Lyon, "Airport Surface Traffic Automation," Lincoln LaboratoryJournal 4:151 (1991).

Reference Link Text
## Colons ##
Reference Link Text

[ Home | Table of Contents| Writing Timeline | Index |Help | Credits]

Copyright ©2001 The McGraw-Hill Companies. Any use is subject to the Terms of Use and Privacy Policy. McGraw-Hill Higher Education is one of the many fine businesses of
The McGraw-Hill Companies, Inc.
Corporate Link