# U.S. Government Printing Office Style Manual/Signs and Symbols

Certain symbols are standardized—number symbols (the digits, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9); letter symbols (the letters of the alphabet, a, b, c, d, etc.); and graphic symbols (the mathematical signs +, -, ±, x, ÷).
The signs +, -, ±, x, and ÷, etc., are closed against accompanying figures and symbols. When the x is used to indicate "crossed with" (in plant or animal breeding) or magnification, it will be separated from the accompanying words by a space.
    i-vii + 1-288 pages
    Early June × Bright (crossed with)
    × 4 (magnification)
    The equation A+B
    The result is 4x4
    miles ÷ gallons
    20,000±5,000
Following a figure, the spelled form is preferred. The percent symbol is used in areas where space will not allow the word percent to be used.
    In that period the price rose 12, 15, and 19 percent.
not In that period the price rose 12 percent, 15 percent, and 19 percent.
Any symbol set close up to figures, such as the degree mark, number mark, dollar mark, or cent mark, is used before or after each figure in a group or series.
    $5 to $8 price range
    5'-7' long, not 5-7' long
    3₵ to 5₵ (no spaces)
    ±2 to ±7; 2°±1°
   * 61 to #64
    but
    § 12 (thin space)
    ❡1951 (thin space)
    from 15 to 25 percent
    45 to 65 °F not 45° to 65° F
Letter symbols are set in italic (see rule 10.8) or in roman (see rule 9.56) without periods and are capitalized only if so shown in copy, since the capitalized form may have an entirely different meaning.
In mathematical equations, use italic for all letter symbols—capitals, lowercase, small capitals, and superiors and inferiors (exponents and subscripts); use roman for figures, including superiors and inferiors.
If an equation or a mathematical expression needs to be divided, break before +, -, =, etc. However, the equal sign is to clear on the left of other beginning mathematical signs.
A short equation in text should not be broken at the end of a line. Space out the line so that the equation will begin on the next line; or better, center the equation on a line by itself.
An equation too long for one line is set flush left, the second half of the equation is set flush right, and the two parts are balanced as nearly as possible.
Two or more equations in a series are aligned on the equal signs and centered on the longest equation in the group.
Connecting words of explanation, such as hence, therefore, and similarly, are set flush left either on the same line with the equation or on a separate line.
Parentheses, braces, brackets, integral signs, and summation signs should be of the same height as the mathematical expressions they include.
Inferiors precede superiors if they appear together; but if either inferior or superior is too long, the two are aligned on the left.
The names and symbols listed below are approved by the International Union of Pure and Applied Chemistry. They are set in roman without periods.
| Element | Symbol | Atomic No. | Element | Symbol | Atomic No. |
| Actinium | Ac | 89 | Mendelevium | Md | 101 |
| Aluminum | Al | 13 | Mercury | Hg | 80 |
| Americium | Am | 95 | Molybdenum | Mo | 42 |
| Antimony | Sb | 51 | Neodymium | Nd | 60 |
| Argon | Ar | 18 | Neon | Ne | 10 |
| Arsenic | As | 33 | Neptunium | Np | 93 |
| Astatine | At | 85 | Nickel | Ni | 28 |
| Barium | Ba | 56 | Niobium | Nb | 41 |
| Berkelium | Bk | 97 | Nitrogen | N | 7 |
| Beryllium | Be | 4 | Nobelium | No | 102 |
| Bismuth | Bi | 83 | Osmium | Os | 76 |
| Bohrium | Bh | 107 | Oxygen | O | 8 |
| Boron | B | 5 | Palladium | Pd | 46 |
| Bromine | Br | 35 | Phosphorus | P | 15 |
| Cadmium | Cd | 48 | Platinum | Pt | 78 |
| Calcium | Ca | 20 | Plutonium | Pu | 94 |
| Californium | Cf | 98 | Polonium | Po | 84 |
| Carbon | C | 6 | Potassium | K | 19 |
| Cerium | Ce | 58 | Praseodymium | Pr | 59 |
| Cesium | Cs | 55 | Promethium | Pm | 61 |
| Chlorine | Cl | 17 | Protactinium | Pa | 91 |
| Chromium | Cr | 24 | Radium | Ra | 88 |
| Cobalt | Co | 27 | Radon | Rn | 86 |
| Copper | Cu | 29 | Rhenium | Re | 75 |
| Curium | Cm | 96 | Rhodium | Rh | 45 |
| Darmstadtium | Ds | 110 | Roentgenium | Rg | 111 |
| Dubnium | Db | 105 | Rubidium | Rb | 37 |
| Dysprosium | Dy | 66 | Ruthenium | Ru | 44 |
| Einsteinium | Es | 99 | Rutherfordium | Rf | 104 |
| Erbium | Er | 68 | Samarium | Sm | 62 |
| Europium | Eu | 63 | Scandium | Sc | 21 |
| Fermium | Fm | 100 | Seaborgium | Sg | 106 |
| Fluorine | Fl | 9 | Selenium | Se | 34 |
| Francium | Fr | 87 | Silicon | Si | 14 |
| Gadolinium | Gd | 64 | Silver | Ag | 47 |
| Gallium | Ga | 31 | Sodium | Na | 11 |
| Germanium | Ge | 32 | Strontium | Sr | 38 |
| Gold | Au | 79 | Sulfur | S | 16 |
| Hafnium | Hf | 72 | Tantalum | Ta | 73 |
| Hassium | Hs | 108 | Technetium | Tc | 43 |
| Helium | He | 2 | Tellurium | Te | 52 |
| Holmium | Ho | 67 | Terbium | Tb | 65 |
| Hydrogen | H | 1 | Thallium | Tl | 81 |
| Indium | In | 49 | Thorium | Th | 90 |
| Iodine | I | 53 | Thulium | Tm | 69 |
| Iridium | Ir | 77 | Tin | Sn | 50 |
| Iron | Fe | 26 | Titanium | Ti | 22 |
| Krypton | Kr | 36 | Tungsten | W | 74 |
| Lanthanum | La | 57 | Uranium | U | 92 |
| Lawrencium | Lr | 103 | Vanadium | V | 23 |
| Lead | Pb | 82 | Xenon | Xe | 54 |
| Lithium | Li | 3 | Ytterbium | Yb | 70 |
| Lutetium | Lu | 71 | Yttrium | Y | 39 |
| Magnesium | Mg | 12 | Zinc | Zn | 30 |
| Manganese | Mn | 25 | Zirconium | Zr | 40 |
| Meitnerium | Mt | 109 | | | |
Symbols duly standardized by any national scientific, professional, or technical group are accepted as preferred forms within the field of the group. The issuing office desiring or requiring the use of such standardized symbols should see that copy is prepared accordingly.
The following list contains some signs and symbols frequently used in printing. The forms and style of many symbols vary with the method of reproduction employed. It is important that editors and writers clearly identify signs and symbols when they appear within a manuscript.
ACCENTS
    ˊ acute
    ˘ breve
    ¸ cedilla
    ˆ circumflex
    ¨ dieresis
    ˋ grave
    ˉ macron
    ˜ tilde
ARROWS
    → direction
    ↖ direction
    ⮣ direction
    ⤴̣ direction
    ⤵̣ direction
    ⬅ bold arrow
    ⇨ open arrow
    ⇄ reversible reaction
BULLETS
    ● solid circle; bullet
    • bold center dot
    • movable accent
CHEMICAL
    ‰ salinity
    ♏︎ minim
    ⇵ exchange
    ↑ gas
CIRCLED SYMBOLS
    ◷ angle in circle
    ⦷ circle with parallel rule
    ⎊ triangle in circle
    ⊙ dot in circle
    ◬⃝ dot in triangle in circle
    ⊕ cross in circle
    © copyright
    ① Ceres
    ② Pallas
    ③ Juno
    ④ Vesta
CODE
    • No. 1 6 pt. code dot
    • No. 2 8 pt. code dot
    • No. 3 10 pt. code dot
    ● No. 4 8 pt. code dot
    ● No. 4 10 pt. code dot
    — No. 1 6 pt. code dash
    — No. 2 8 pt. code dash
    — No. 3 10 pt. code dash
    ➖ No. 4 8 pt. code dash
    ➖ No. 4 10 pt. code dash
COMPASS
    ° degree
    °̣ degree with period
    ′ minute
    ′̣ minute with period
    ″ second
    ″̣ second with period
    ″̲ canceled second
DECORATIVE
    ✚ bold cross
    ✠ cross patte
    cross patte
    cross patte
    🏶 (184 N)
    🗝 key
    ❦ (206 N)
    ¶ paragraph
ELECTRICAL
    𝓡 reluctance
    ↔ reaction goes both right and left
    ↕ reaction goes both up and down
    ↕ reversible
    → direction of flow; yields
    → direct current
    ⇆ electrical current
    ⇆ reversible reaction
    ⇄ reversible reaction
    ⇆ alternating current
    ⇄ alternating current
    ⇌ reversible reaction beginning at left
    ⇋ reversible reaction beginning at right
    Ω ohm; omega
    MΩ megohm; omega
    μΩ microohm; mu omega
    ω angular frequency, solid angle; omega
    Φ magnetic flux; phi
    Ψ, dielectric flux; electrostatic flux; psi
    γ conductivity; gamma
    ρ resistivity; rho
    Λ equivalent conductivity
    HP horsepower
MATHEMATICAL
    ̅ vinculum (above letters)
    ∺ geometrical proportion
    ∹ difference, excess
    ∥ parallel
    ∥s parallels
    ∦ not parallels
    | | absolute value
    ∙ multiplied by
    ∶ is to; ratio
    ÷ divided by
    ∴ therefore; hence
    ∵ because
    ∷ proportion; as
    ≪ is dominated by
    > greater than
    ⫍ greater than
    ≥ greater than or equal to
    ≧ greater than or equal to
    ≷ greater than or less than
    ≯ is not greater than
    < less than
    ⫎ less than
    ≶ less than or greater than
    ≮ is not less than
    ⪪ smaller than
    ≤ less than or equal to
    ≦ less than or equal to
    ≧ or ≥ greater than or equal to
    ⋜ equal to or less than
    ⪙ equal to or less than
    ⪚ is not greater than equal to or less than
    ⋝ equal to or greater than
    ⪚ is not less than equal to or greater than
    ⫨ equilateral
    ⊥ perpendicular to
    ⊢ assertion sign
    ≐ approaches
    ≐ approaches a limit
    ≚ equal angles
    ≠ not equal to
    ≡ identical with
    ≢ not identical with
    score
    ≈ or ≒ nearly equal to
    = equal to
    ~ difference
    ≃ perspective to
    ≅ congruent to approximately equal
    ≏ difference between
    ≎ geometrically equivalent to
    ( included in
    ) excluded from
    ⊂ is contained in
    ∪ logical sum or union
    ∩ logical product or intersection
    √ radical
    √ root
    ${\sqrt[{2}]}$ square root
    ${\sqrt[{3}]}$ cube root
    ${\sqrt[{4}]}$ fourth root
    ${\sqrt[{5}]}$ fifth root
    ${\sqrt[{6}]}$ sixth root
    π pi
    ϵ base (2.718) of natural system of logarithms; epsilon
    ∈ is a member of; dielectric constant; mean error; epsilon
    + plus
    ➕ bold plus
    − minus
    ➖ bold minus
    / shill(ing); slash; virgule
    ± plus or minus
    ∓ minus or plus
    × multiplied by
    = bold equal
    # number
    ⅌ per
    % percent
    ∫ integral
    | single bond
    \ single bond
    / single bond
    || double bond
    \\ double bond
    // double bond
    ⌬ benzene ring
    ∂ or δ differential; variation
    ∂ Italian differential
    → approaches limit of
    ∿ cycle sine
    ∫ horizontal integral
    ∮ contour integral
    ∝ variation; varies as
    ∏ product
    ∑ summation of; sum; sigma
    ! or ∟ factorial product
MEASURE
    ℔ pound
    ʒ dram
    ƒʒ fluid dram
    ℥ ounce
    ƒ℥ fluid ounce
    O pint
MISCELLANEOUS
    § section
    † dagger
    ‡ double dagger
    ℀ account of
    ℅ care of
    score
    ¶ paragraph
    þ Anglo-Saxon
    ℄ center line
    ☌ conjunction
    ⊥ perpendicular to
    " or “ ditto
    ∝ variation
    ℞ recipe
    ⊏ move right
    ⊐ move left
    ○ or ⊙ or ① annual
    ⊙⊙ or ② biennial
    ∈ element of
    ℈ scruple
    ƒ function
    ! exclamation mark
    ⊞ plus in square
    ♃ perennial
​⌀ diameter c̄ mean value of c ∪ mathmodifier ⊂ mathmodifier ⊡ dot in square ◬ dot in triangle ⊠ station mark @ at
MONEY
¢ cent ¥ yen £ pound sterling ₥ mills
MUSIC
♮ natural ♭ flat ♯ sharp
PLANETS
☿ Mercury ♀ Venus 🜨 Earth ♂ Mars ♃ Jupiter ♄ Saturn ⛢ Uranus ♆ Neptune ♇ Pluto ☊ dragon's head, ascending node ☋ dragon's tail, descending node ☌ conjunction ☍ opposition ☉ or 🌞︎ Sun ☉̲ Sun's lower limb ☉̅ Sun's upper limb ⦶ solar corona 🜨 solar halo ◍ Moon 🌑︎ new Moon ☽ first quarter 🌓︎ first quarter 🌘︎ third quarter 🌗︎ last quarter ☾ last quarter 🌗︎ last quarter 🌕︎ full Moon 🌝︎ full Moon ☉̶ eclipse of Moon lunar halo lunar corona ⚳ Ceres ⚵ Juno
PUNCTUATION
{ } braces [ ] brackets ( ) parentheses ⟨ ⟩ square parentheses; angle brackets ¡ Spanish open quote ¿ Spanish open quote
SEX
♂ or ♁ male □ male, in charts ♀ female ○ female, in charts ⚥ hermaphrodite
SHAPES
◆ solid diamond ◇ open diamond ○ circle ▲ solid triangle △ triangle □ square ■ solid square ▱ parallelogram
▭ rectangle ⧉ double rectangle ★ solid star ☆ open star ∟ right angle ∠ angle √ check ✓ check ß German ss ß italic German ss ☛ solid index ☚ solid index ☞ index ☜ index
GEOLOGIC SYSTEMS
Q Quaternary T Tertiary K Cretaceous J Jurassic 🝈 Triassic P Permian ℙ Pennsylvanian M Mississippian D Devonian S Silurian O Ordovician Ꞓ Cambrian pꞒ Precambrian C Carboniferous
VERTICAL
5 unit vertical 8 point vertical 9 unit vertical
WEATHER
⊤ thunder ☈ thunderstorm; sheet lightning ☇ sheet lightning ↓ precipitate ◍ rain ← floating ice crystals ↔ ice needles
▲ hail 🝴 sleet glazed frost ⏘ hoarfrost ⌵ frostwork ∗ snow or sextile ⊠ snow on ground drifting snow (low) fog haze Aurora
ZODIAC
♈︎ Aries; Ram ♉︎ Taurus; Bull ♊︎ Gemini; Twins ♋︎ Cancer; Crab ♌︎ Lion ♍︎ Virgo; Virgin ♎︎ Libra: Balance ♏︎ Scorpio; Scorpion ♐︎ Sagittarius; Archer ♑︎ Capricornus; Goat ♒︎ Aquarius; Water bearer ♓︎ Pisces; Fishes