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When using percentages within body copy, the number is expressed in figures, even when it is less than 10, and the word percent is used. (Note: Percent is one word and is singular.)

  • Sam Rich said 8 percent of the population is eligible for the program.

The percent symbol (%) should be used only in charts and figures or in scientific or statistical copy. (CM15 9.19; CM14 8.18)


As area codes are now required in most phone dialing, omit parentheses and use hyphens when listing phone or fax numbers.

  • 412-624-4147
  • Not:
  • (412) 624-4147 or 412.624.4147

Use the 1 in front of toll-free numbers.

  • 1-800-123-4567 or 1-877-987-6543


Avoid the use of Pittsburghese, as in the following:

  • The clothes need washed.
  • The dog needs out.

Say/write instead:

  • The clothes need to be washed.
  • The dog needs to go out.


Follow guidelines as published in CM15 7.6–30 and CM14 6.7–30 and 6.82 except for words that end in s.

  • dos and don’ts
  • MDs, MBAs, PhDs
  • in twos and threes
  • the early 1920s; in the ’70s
  • p’s and q’s
  • straight A’s
  • Texas’ population
  • Jones’ car


See Capitalization section.


See Departments, Offices, Programs, Schools section.


See Hyphens, Compounds section, item 7.


See Endowed Chairs, Professorships section.


The word proved is always either a verb or part of a verb phrase.

  • Joe proved the problem existed.
  • Joe has proved the problem existed.

Use the word proven only as an adjective.

  • The medicine was a proven remedy.