Compounding Rules
105
6.38.
Print a hyphen between the elements of a fraction, but omit it between the numerator and the denominator when the hyphen appears in either or in both.
- one-thousandth
- two-thirds
- two one-thousandths
- twenty-three thirtieths
- twenty-one thirty-seconds
- three-fourths of an inch
6.39.
A unit modifier following and reading back to the word or words modified takes a hyphen and is printed in the singular.
- motor, alternating-current, 3-phase, 60-cycle, 115-volt
- glass jars: 5-gallon, 2-gallon, 1-quart
- belts: 2-inch, 1¼-inch, ½-inch, ¼-inch
Civil and military titles
6.40.
Do not hyphenate a civil or military title denoting a single office, but print a double title with a hyphen.
- ambassador at large
- assistant attorney general
- commander in chief
- comptroller general
- Congressman at Large
- major general
- notary public
- secretary general
- secretary-treasurer
- sergeant at arms
- treasurer-manager
- under secretary
- but under-secretaryship
- vice president
- but vice-presidency
6.41.
The adjectives elect and designate, as the last element of a title, require a hyphen.
- President-elect (Federal)
- ambassador-designate
- Vice-President-elect (Federal)
- minister-designate
- Secretary of Housing and Urban Development-designate
