# U.S. Government Printing Office Style Manual/Compounding Rules

A compound word is a union of two or more words, either with or without a hyphen. It conveys a unit idea that is not as clearly or quickly conveyed by the component words in unconnected succession. The hyphen is a mark of punctuation that not only unites but separates the component words, and thus facilitates understanding, aids readability, and ensures correct pronunciation. When compound words must be divided at the end of a line, such division should be made leaving prefixes and combining forms of more than one syllable intact.
In applying the rules in this chapter and in using the list of examples in the following chapter, "Compounding Examples," the fluid nature of our language should be kept in mind. Word forms constantly undergo modification. Two-word forms, which often acquired the hyphen first, frequently bypass the hyphen stage and instantly assume a one-word form.
The rules, therefore, are somewhat flexible. Exceptions must necessarily be allowed. Current language trends continue to point to closing up certain words which, through either frequent use or widespread dissemination through modern media exposure, have become fixed in the reader's mind as units of thought. The tendency to merge two short words continues to be a natural progression toward better communication.
In general, omit the hyphen when words appear in regular order and the omission causes no ambiguity in sense or sound.
    banking hours
    blood pressure
    book value
    census taker
    day laborer
    eye opener
    fellow citizen
    living costs
    palm oil
    patent right
    real estate
    rock candy
    training ship
    violin teacher
Words are usually combined to express a literal or nonliteral (figurative) unit idea that would not be as clearly expressed in unconnected succession.
    afterglow
    bookkeeping
    cupboard
    forget-me-not
    gentleman
    newsprint
    right-of-way
    whitewash
A derivative of a compound retains the solid or hyphenated form of the original compound unless otherwise indicated.
    coldbloodedness
    footnoting
    ill-advisedly
    outlawry
    praiseworthiness
    railroader
    Y-shaped
A hyphen is used to avoid doubling a vowel or tripling a consonant, except after the short prefixes co, de, pre, pro, and re, which are generally printed solid. (See also rules 6.29 and 6.32.)
    cooperation
    deemphasis
    preexisiting
    anti-inflation
    micro-organism
    semi-independent
    brass-smith
    Inverness-shire
    thimble-eye
    ultra-atomic
    shell-like
    hull-less
    but
    co-occupant
    cross section
Print solid two nouns that form a third when the compound has only one primary accent, especially when the prefixed noun consists of only one syllable or when one of the elements loses its original accent.
    airship
    bathroom
    bookseller
    cupboard
    dressmaker
    fishmonger
    footnote
    locksmith
    workman
Print solid a noun consisting of a short verb and an adverb as its second element, except when the use of the solid form would interfere with comprehension.
    blowout
    breakdown
    hangover
    holdup
    makeready
    markoff
    pickup
    builddown
    cooldown
    runoff
    setup
    showdown
    thowaway
    tradeoff
    flareback
    giveaway
    but
    cut-in
    phase-in
    run-in
    sit-in
Compounds beginning with the following nouns are usually printed solid.
    book
    eye
    horse
    house
    mill
    play
    school
    shop
    way
    wood
    work
Compounds ending in the following are usually printed solid, especially when the prefixed word consists of one syllable.
    berry
    bird
    blossom
    board
    boat
    book
    borne
    bound
    box
    boy
    brained
    bug
    bush
    cam
    craft
    field
    fish
    flower
    fly
    girl
    grower
    headed
    hearted
    holder
    hopper
    house
    keeper
    keeping
    land
    light
    like
    line
    load
    maid
    maker
    making
    man
    master
    mate
    mill
    mistress
    monger
    over
    owner
       but #ownership
    person
    picker
    picking
    piece
    plane
    power
    proof
    roach
    room
    shop
    site
    skin
    smith
    stone
    store
    tail
    tight
    time (not clock)
    ward
    ware
    water
    way
    wear
    weed
    wide
    wise
    woman
    wood
    work
    worker
    working
    worm
    worthy
    writer
Print solid any, every, no, and some when combined with body, thing, and where. When one is the second element, print as two words if meaning a single or particular person or thing. To avoid mispronunciation, print no one as two words at all times.
    anybody
    anything
    anywhere
    anyone
    everybody
    everything
    everywhere
    everyone
    nobody
    nothing
    nowhere
    no one
    somebody
    something
    somewhere
    someone
but any one of us may stay; every one of the pilots is responsible; every body was accounted for
Print compound personal pronouns as one word.
    herself
    himself
    itself
    myself
    oneself
    ourselves
    themselves
    thyself
    yourself
    yourselves
Print as one word compass directions consisting of two points, but use a hyphen after the first point when three points are combined.
    northeast
    southwest
    north-northeast
    south-southwest
also north-south alignment
    agreed-upon standards
    Federal-State-local cooperation
    Baltimore-Washington road
    German-English descent
    collective-bargaining talks
    guided-missile program
    contested-election case
    hearing-impaired class
    contract-bar rule
    high-speed line
    cost-of-living increase
    large-scale project
    drought-stricken area
    law-abiding citizen
    English-speaking nation
    long-term loan
    fire-tested material
    line-item veto
    long-term-payment loan
    low-cost housing
    lump-sum payment
    most-favored-nation clause
    multiple-purpose uses
    no-par-value stock
    one-on-one situation
    part-time personnel
    rust-resistant covering
    service-connected disability
    state-of-the-art technology
    supply-side economics
    tool-and-die maker
    up-or-down vote
    U.S.-owned property; U.S.-flagship
    1-inch diameter; 2-inch-diameter pipe
    a 4-percent increase, the 10-percent rise
    but
    4 percent citric acid
    4 percent interest. (Note the absence of an article: a, an, or the. The word of is understood here.)
Where meaning is clear and readability is not aided, it is not necessary to use a hyphen to form a temporary or made compound. Restraint should be exercised in forming unnecessary combinations of words used in normal sequence.
    atomic energy power
    bituminous coal industry
    child welfare plan
    civil rights case
    civil service examination
    durable goods industry
    flood control study
    free enterprise system
    ground water levels
    high school student
    elementary school grade
    income tax form
    interstate commerce law
    land bank loan
    land use program
    life insurance company
    mutual security funds
    national defense appropriation
    natural gas company
    per capita expenditure
    Portland cement plant
    production credit loan
    public at large
    public utility plant
    real estate tax
    small businessman
    Social Security pension
    soil conservation measures
    special delivery mail
    parcel post delivery
    speech correction class
but no-hyphen rule (readability aided); not no hyphen rule
Print without a hyphen a compound predicate adjective or predicate noun the second element of which is a present participle.
    The duties were price fixing.
    The shale was oil bearing.
    The effects were far reaching.
    The area is used for beet raising.
Print without a hyphen a compound predicate adjective the second element of which is a past participle. Omit the hyphen in a predicate modifier of comparative or superlative degree.
    The area is drought stricken.
    This material is fire tested.
    The paper is fine grained.
    The cars are higher priced.
    Moderately fine grained wood.
    The reporters are better informed.
Print without a hyphen a two -word modifier the first element of which is a comparative or superlative.
    better drained soil
    best liked books
    higher level decision
    highest priced apartment
    larger sized dress
    better paying job
    lower income group
    but
    uppercrust society
    lowercase, uppercase type
    upperclassman
    bestseller (noun)
    lighter-than-air craft
    higher-than-market price
Do not use a hyphen in a two-word unit modifier the first element of which is an adverb ending in ly, nor use hyphens in a three-word unit modifier the first two elements of which are adverbs.
    eagerly awaited moment
    wholly owned subsidiary
    unusually well preserved specimen
    very well defined usage
    longer than usual lunch period
    still-lingering doubt
    not too distant future
    most often heard phrase
    but
    ever-normal granary
    ever-rising flood
    still-new car
    well-known lawyer
    well-kept secret
Proper nouns used as unit modifiers, either in their basic or derived form, retain their original form; but the hyphen is printed when combining forms.
    Latin American countries
    North Carolina roads
    a Mexican-American
    South American trade
    Spanish-American pride
    Winston-Salem festival
    African-American program
    Anglo-Saxon period
    Franco-Prussian War
    Seventh-day Adventists
    but
    Minneapolis-St. Paul region
    North American-South American sphere
    French-English descent
    Washington-Wilkes-Barre route or Washington/Wilkes-Barre route
    elderly clothesman
    old-clothes man
    competent shoemaker
    wooden-shoe maker
    field canning factory
    tomato-canning factory
    brave servicemen
    service men and women
    light blue hat (weight)
    light-blue hat (color)
    average taxpayer
    income-tax payer
    American flagship (military)
    American-flagship
    well-trained schoolteacher
    elementary school teacher
    preschool children (kindergarten)
    pre-school children (before school)
    rezoned wastesite
    hazardous-waste site
    but
    common stockholder
    stock ownership
    small businessman
    working men and women
    steam powerplant site
    meat packinghouse owner
    2- to 3- and 4- to 5-ton trucks
    2- by 4-inch boards, but boards 2 to 6 inches wide
    8-, 10-, and 16-foot boards
    6.4-, 3.1-, and 2-percent pay raises
    moss- and ivy-covered walls, not moss and ivy-covered walls
    long- and short-term money rates, not long and short-term money rates
but twofold or threefold, not two or threefold
    goat, sheep, and calf skins, not goat, sheep, and calfskins
    intrastate and intracity, not intra-state and -city
    American owned and managed companies
    preoperative and postoperative examination
    ante bellum days
    bona fide transaction
    ex officio member
    per capita tax
    per diem employee
    prima facie evidence
    abstract B pages
    article 3 provisions
    class II railroad
    grade A milk
    point 4 program
    ward D beds
    "blue sky" law
    "good neighbor" policy
    "tie-in" sale
    but
    right-to-work law
    line-item veto
    bluish green
    dark green
    orange red
    bluish-green feathers
    iron-gray sink
    silver-gray body
    big gray cat
    a fine old southern gentleman
    afterbirth
    Anglomania
    antedate
    antislavery
    biweekly
    bylaw
    circumnavigation
    cisalpine
    cooperate
    contraposition
    countercase
    deenergize
    demitasse
    excommunicate
    extracurricular
    foretell
    heroicomic
    hypersensitive
    hypoacid
    inbound
    infrared
    interview
    intraspinal
    introvert
    isometric
    macroanalysis
    mesothorax
    metagenesis
    microphone
    misstate
    monogram
    multicolor
    neophyte
    nonneutral
    offset
    outbake
    overactive
    pancosmic
    paracentric
    particoated
    peripatetic
    planoconvex
    polynodal
    postscript
    preexist
    proconsul
    pseudoscholastic
    reenact
    retrospect
    semiofficial
    stepfather
    subsecretary
    supermarket
    thermocouple
    transonic
    transship
    tricolor
    ultraviolet
    unnecessary
    underflow
    portable
    geography
    procurement
    coverage
    manhood
    innermost
    operate
    selfish
    partnership
    plebiscite
    pumpkin
    lonesome
    twenty fold
    meatless
    homestead
    spoonful
    outlet
    northward
    kilogram
    wavelike
    clockwise
    lifelike
    lilylike
    girllike
    bell-like
    Scotland-like
    McArtor-like
    anti-hog-cholera serum
    co-occurrence
    co-op
    mid-decade
    multi-ply (several plies)
    non-civil-service position
    non-tumor-bearing tissue
    pre-midcourse review
    pre-position (before)
    pro-choice
    pro-life
    re-cover (cover again)
    re-creation (create again)
    re-lay (lay again)
    re-sorting (sort again)
    re-treat (treat again)
    un-ionized
    un-uniformity
    but
    rereferred
    rereviewed
    re-redirect
    sub-subcommittee
    super-superlative
    ex-governor
    ex-serviceman
    ex-son-in-law
    ex-vice-president
    self-control
    self-educated
    quasi-academic
    quasi-argument
    quasi-corporation
    quasi-young
    but
    selfhood
    selfsame
Unless usage demands otherwise, use a hyphen to join a prefix or combining form to a capitalized word. (The hyphen is retained in words of this class set in caps.)
    anti-American
    pro-British
    un-American
    non-Government
    neo-Nazi
    post-World War II or post-Second World War
    non-Federal
    but
    nongovernmental
    overanglicize
    transatlantic
Print a hyphen between the elements of compound numbers from twenty-one to ninety-nine and in adjective compounds with a numerical first element.
    twenty-one
    twenty-first
    6-footer
    6-foot-ll-inch man
    24-inch ruler
    3-week vacation
    8-hour day
    10-minute delay
    20th-century progress
    3-to-l ratio
    5-to-4vote
    .22-caliber cartridge
    2-cent-per-pound tax
    four-in-hand tie
    three-and-twenty
    two-sided question
    multimillion-dollar fund
    10-dollar-per-car tax
    thirty- (30-) day period
    but
    one hundred twenty-one
    100-odd
    foursome
    threescore
    foursquare
    $20 million airfield
    second grade children
Print without a hyphen a modifier consisting of a possessive noun preceded by a numeral. (See also rule 8.14.)
    1 month's layoff
    3 weeks' vacation
    1 week's pay
    1 minute's delay
    2 hours' work
but a 1-minute delay
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
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
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
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
Do not print a hyphen in scientific terms (names of chemicals, diseases, animals, insects, plants) used as unit modifiers if no hyphen appears in their original form.
    carbon monoxide poisoning
    guinea pig raising
    hog cholera serum
    methyl bromide solution
    stem rust control
    equivalent uranium content
    whooping cough remedy
    but
    Russian-olive plantings
    Douglas-fir tree
Chemical elements used in combination with figures use a hyphen, except with superior figures.
    Freon-12
    polonium-210
    uranium-235
    U$^{235}$
    Sr$^{90}$
    $_{92}$U$^{234}$
Note use of hyphens and closeup punctuation in chemical formulas.
    9-nitroanthra(1,9,4,10)bis(1)oxathiazone-2,7-bisdioxide
    Cr-Ni-Mo
    2,4-D
Print a hyphen between the elements of technical or contrived compound units of measurement.
    candela-hour
    crop-year
    horsepower-hour
    light-year
    passenger-mile
    staff-hour
    work-year
but kilowatthour
Print with a hyphen the elements of an improvised compound.
    blue-pencil (v.)
    18-year-old (n., u.m.)
    know-it-all (n.)
    know-how (n.)
    lick-the-finger-and-test-the-wind economics
    make-believe (n., u.m.)
    one-man-one-vote principle
    roll-on/roll-off ship
    George "Pay-As-You-Go" Miller
    stick-in-the-mud (n.)
    let-George-do-it attitude
    how-to-be-beautiful course
    hard-and-fast rule
    penny-wise and pound-foolish policy
    first-come-first- served basis
but a basis of first come, first served
Use hyphens in a prepositional-phrase compound noun consisting of three or more words.
    cat-o'-nine-tails
    government-in-exile
    grant-in-aid
    jack-in-the-box
    man-of-war
    mother-in-law
    mother-of-pearl
    patent-in-fee
    but
    heir at law
    next of kin
    officer in charge
When the corresponding noun form is printed as separate words, the verb form is always hyphenated.
    cold-shoulder
    blue-pencil
    cross-brace
Print a hyphen in a compound formed of repetitive or conflicting terms and in a compound naming the same thing under two aspects.
    boogie-woogie
    comedy-ballet
    dead-alive
    devil-devil
    even-stephen
    farce-melodrama
    fiddle-faddle
    hanky-panky
    murder-suicide
    nitty-gritty
    pitter-patter
    razzle-dazzle
    walkie-talkie :nitwit
    willy-nilly
    young-old
    but
    bowwow
    dillydally
    hubbub
    riffraff
Use a hyphen in a nonliteral compound expression containing an apostrophe in its first element.
    asses'-eyes
    ass's-foot
    bull's-eye
    cat's-paw
    crow's-nest
Use a hyphen to join a single capital letter to a noun or a participle.
    H-bomb
    I-beam
    T-shaped
    U-boat
    C-chip
    C-section
    V-necked
    S-iron
    T-square
    X-ed out
    but
    x ray
    x raying
    S turns
Print idiomatic phrases without hyphens.
    come by
    inasmuch as
    insofar as
    Monday week
    nowadays