Numbers and dates

We follow the Chicago Manual of Style here. The IT Communications Office (ITCO) says it best:

Number formatting: Zero through nine, 10 and up.

Date formatting: July 1 (add the year if date is more than one year prior/after)

See ITCO’s style guide for more information.

Percentages

Use the percent sign (%) in these circumstances:

• Tables and in technical or scientific writing. For example: 60% of participants reported experiencing negative side effects.
• Headings and subheadings. For example: Candidate Woof takes 7% lead in the election for best dog.
• Interface labels
• Captions and infographics

The percent sign in these cases improves content’s scannability. Otherwise, spell out percent in body copy.