Abbreviations and Acronyms

Abbreviations (the shortened form of a word or phrase) and acronyms (words formed from the initial letters of a phrase) are commonly used in technical writing. In some fields, including chemistry, medicine, computer science, and geographic information systems, acronyms are used so frequently that the reader can feel lost in an alphabet soup. However, the proper use of these devices enhances the reading process, fostering fluid readability and efficient comprehension.

Some style manuals devote entire chapters to the subject of abbreviations and acronyms, and your college library no doubt contains volumes that you can consult when needed. Here, I provide just a few principles you can apply in using abbreviations and acronyms, and in the next section I offer a table of some of the forms most commonly used by student writers.


  • Typically, abbreviate social titles (Ms., Mr.) and professional titles (Dr., Rev.).
  • In resumes and cover letters, avoid abbreviations representing titles of degrees (e.g., write out rather than abbreviate “Bachelor of Science”).
  • Follow most abbreviations with a period, except those representing units of measure (“Mar.” for March; “mm” for millimeter). See the table that follows for further guidance.
  • Typically, do not abbreviate geographic names and countries in text (i.e., write “Saint Cloud” rather than “St. Cloud”; write “United States” rather than “U.S.”). However, these names are usually abbreviated when presented in “tight text” where space can be at a premium, as in tables and figures.
  • Use the ampersand symbol (&) in company names if the companies themselves do so in their literature, but avoid using the symbol as a narrative substitute for the word “and” in your text.
  • In text, spell out addresses (Third Avenue; the Chrysler Building) but abbreviate city addresses that are part of street names (Central Street SW).
  • Try to avoid opening a sentence with an abbreviation; instead, write the word out.


  • Always write out the first in-text reference to an acronym, followed by the acronym itself written in capital letters and enclosed by parentheses. Subsequent references to the acronym can be made just by the capital letters alone. For example:
    • Geographic Information Systems (GIS) is a rapidly expanding field. GIS technology . . .
  • Unless they appear at the end of a sentence, do not follow acronyms with a period.
  • Generally, acronyms can be pluralized with the addition of a lowercase “s” (“three URLs”); acronyms can be made possessive with an apostrophe followed by a lowercase “s” (“the DOD’s mandate”).
  • As subjects, acronyms should be treated as singulars, even when they stand for plurals; therefore, they require a singular verb (“NIOSH is committed to . . .”).
  • Be sure to learn and correctly use acronyms associated with professional organizations or certifications within your field (e.g., ASME for American Society of Mechanical Engineers; PE for Professional Engineer).
  • With few exceptions, present acronyms in full capital letters (FORTRAN; NIOSH). Some acronyms, such as “scuba” and “radar,” are so commonly used that they are not capitalized. Consult the table that follows in the next section to help determine which commonly used acronyms do not appear in all capital letters.
  • When an acronym must be preceded by “a” or “an” in a sentence, discern which word to use based on sound rather than the acronym’s meaning. If a soft vowel sound opens the acronym, use “an,” even if the acronym stands for words that open with a hard sound (i.e., “a special boat unit,” but “an SBU”). If the acronym opens with a hard sound, use “a” (“a KC-135 tanker”).

Click here to download a pdf of a table of commonly used abbreviations and acronyms.

Spelling, Capitalization, and Punctuation

Use this table to check the proper spelling, capitalization, and punctuation of commonly used abbreviations and acronyms. For a much more detailed listing of abbreviations and acronyms, you can check in the back pages of many dictionaries, or consult the free online version of the United States Government Printing Office Style Manual.

A or amp ampere
a.m. ante meridiem, before noon
Assembler Assembler computer language
atm standard atmosphere
Ave. avenue
B.A. Bachelor of Arts
BASIC BASIC computer language
Blvd. boulevard
BP boiling point
B.S. Bachelor of Science
Btu British thermal unit
oC degrees Celsius
cd  candela
CDC  Centers for Disease Control
CFR  Code of Federal Regulations
CIA  Central Intelligence Agency
cm  centimeter
COBOL  COBOL computer language
Corp.  corporation
D  darcy
DEP Department of Environmental Protection
DOD Department of Defense
DOT Department of Transportation
engg. engineering
engr. engineer
e.g. exempli gratia, for example
EPA Environmental Protection Agency
et al.  et alii, and others
etc. et cetera, and so forth
oF degrees Fahrenheit
FBI Federal Bureau of Investigation
FCC Federal Communications Commission
FDA Food and Drug Administration
fig. figure
FORTRAN FORTRAN computer language
ft foot
gal. gallon
ha hectare
h hour
HP horsepower
HTML hypertext markup language
Hz hertz
i.e. id est, that is
in inch
Inc. incorporated
K Kelvin
kg kilogram
kw kilowatt
kWh kilowatt-hour
l or L liter
LAFTA Latin American Free Trade Association
lb pound
m meter
mHz megahertz
min. minute
mol mole
M.S. Master of Science
NASA National Aeronautics and Space Administration
neg negative
NIH National Institutes of Health
NIOSH National Institute for Occupational Safety and Health
 NM  nautical mile
 NOAA  National Oceanic and Atmospheric Administration
 NSF  National Science Foundation
 OPEC  Organization of Petroleum Exporting Countries
 OSHA Occupational Safety and Health Administration
p. page
Pascal  Pascal computer language
 Ph.D.  Philosophiae Doctor, Doctor of Philosophy
 p.m.  post meridiem, after noon
 pos  positive
 pp. pages
pt. pint
qt. quart
radar  radio detecting and ranging
 RPM  revolutions per minute
 scuba  self-contained underwater breathing apparatus
 sec. or s  second
 sq  square
 STP  standard temperature and pressure
 temp  temperature
 Univ.  university
 URL  uniform resource locator
 USGS  United States Geological Survey
 vol.  volume