151 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.
Abbreviations
- 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.
- When presenting a references page, follow the conventions of abbreviation employed by a journal in your field. To preserve space, many journals commonly use abbreviations, without periods, in their references pages (e.g., “J” for Journal; “Am” for “American”).
Acronyms
- 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.
Self-Study
For comprehensive online acronyms dictionaries, especially for technical fields such as chemistry and medicine, I recommend these sites:
Table of commonly used abbreviations and acronyms:
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 Chicago Manual of Style (also available online to subscribers) or 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 |