Kaplan University Writing Center
Abbreviations
Abbreviations are shortened words or phrases commonly used in scientific writing to express
units of measurement, chemicals (Figure 1), and statistical data. There are also several uses of
abbreviations in academic and professional writing that this resource will explain.
Table of Contents
Titles of Address and Credentials
Dates and Numbers
Acronyms
Latin Terms
Commonly Misused Abbreviations
Figure 1. Doodle with chemical
abbreviations.
Titles of Address and Credentials
Abbreviations for honorifics such as titles of address and rank come before a person’s name
whereas suffixes such as junior, senior, the second, and the third, etc. and degree credentials
come after a person’s name. Refer to Table 1 for examples and the conditions of usage.
Table 1.
Abbreviations for Titles and Credentials with Names
Honorific
Usage
Word  Abbreviation
Examples
Title of
address
Use before surnames or full
names.
Missus  Mrs.
Mrs. O’Brien
Mister  Mr.
Mr. David C. Graham
Doctor  Dr.
Dr. Lopez
Use before full names only.
General  Gen.
Ranks and honorifics are
spelled out when they come
before the surname only.
Senator  Sen.
Gen. Dwight D.
Eisenhower
Use after full names.
senior  Sr.
Harry Connick Sr.
(In an APA reference
citation, a comma
separates the surname and
suffix.)
junior  Jr.
James R. Smith Jr.
the second  II
Francis Rivera II
Title of rank
Sequence,
suffix
abbreviations
Professor  Prof.
Sen. Hillary R. Clinton
Prof. John Nash
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Credentials
Use after full name and a
comma.
Do not to use internal
periods or spaces in
acronyms of capital letters.
Bachelor of Arts  BA
Melinda Merritt, BA
Master of Business
Administration  MBA
Leah Spalding, MBA
Doctor of Philosophy 
PhD
Ricardo Swans, PhD
Marvin Laski, Esq.
Esquire  Esq.
Dates and Numbers
In academic and professional writing, the days of the week, months, and the words day, week,
month, and year are spelled out in the text as are numbers one through nine unless they are
expressing numerical values of time, dates, ages, mathematical equations, money, scores,
percentages, and other data. Refer to Table 2 for examples.
Table 2.
Abbreviations for Dates and Numbers
Types
Usage
Phrase 
Abbreviation
Examples
Calendar eras
Use to indicate whether the
event occurred in the last
two thousand years.
Common Era  CE
2016 CE
Anno Domini (in the
year of the Lord AD
AD 1492
CE and AD refer to the
same era, and BCE and BC
refer to the same era. CE
and BCE are the preferred
abbreviations in academic
style as they are inclusive
of all religions.
Before the Common
Era  BCE
Before Christ  BC
1178 BCE
585 BC
Augustus, the first
Roman Emperor,
lived from 63 BCE to
14 CE.
Use AD before the year and
CE, BCE, or BC after the
year.
Units of time
Use only when
accompanied by the
number or unit of time.
hours  hr
1 hr 30 min
minutes  min
3 hr 1min
milliseconds  ms
49 ms
nanoseconds  ns
30 ns
seconds  s
40 min 6 s
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Clock time
Use only when
accompanied by the time.
ante meridiem (before
noon or morning) 
a.m.
post meridiem
(afternoon or evening)
 p.m.
8:00 a.m.
1:00 p.m.
His alarm went off at
5 in the morning.
His alarm when off at
5:00 a.m.
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Acronyms
Acronyms are uppercase, pronounceable
abbreviations made from the first letter of each
word of a name as in NATO for North Atlantic
Treaty Organization (Figure 2). With the
exception of acronyms treated as words,
acronyms are used in a text only after the full
name or title has been spelled out. Refer to
Table 3 for examples.
Figure 2. Map of the 28 NATO members. NATO is
the acronym for the North Atlantic Treaty Organization
Table 3.
Acronyms and the Conditions of Usage
Types
Usage
Examples
Common
Acronyms
Write out the full name the
first time it is used in text
and add the acronym in
parentheses after it and
then use just the acronym
in the next uses.
Mothers Against Drunk Driving (MADD)
Do not use a period or
space between the letters
when the acronym is being
used as a noun: I live in the
USA. Use periods when
US or USA is being used as
an adjective: He works for
the U.S. government.
National Association for the Advancement of
Colored People (NAACP)
National Aeronautics and Space Administration
(NASA)
National Organization for Women (NOW)
International Standard Book Number (ISBN)
Most Valuable Player (MVP)
Veterans of Foreign Wars (VFW)
United States of America (USA)
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Acronyms
considered
words
These acronyms appear in
the dictionary as words and
may be treated as words in
the text. Per APA (2010),
these acronyms do not
need to be explained; the
acronym alone may be
used for the first use as well
as the subsequent uses in
the text.
IQ (intelligence quotient)
REM (rapid eye movement)
ESP (extrasensory perception)
AIDS (acquired immune deficiency syndrome)
HIV (Human Immunodeficiency virus)
NADP (Nicotinamide adenine dinucleotide
phosphate)
ACTH (Adrenocorticotropic hormone)
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Latin Terms
In academic and professional writing, several Latin expressions are commonly used in
footnotes, references, and parenthetical material. When these expressions are used in
sentences, they should be spelled out in English instead. Refer to Table 4 for examples.
Table 4.
Latin Terms
Usage of Latin Abbreviations
English (Latin)  Abbreviation
Use Latin abbreviations in parenthetical
material only with the exception of v.
(versus) in the context of a court case and
et al. (and others), both of which may be
used in the body text as well.
for example (exempli gratia)  e.g.,
Use the English spelling when using these
terms in the body text (outside of
parentheses or footnotes).
namely (videlicet)
The examples show standard comma use
with these abbreviations.
against, versus
and others (et alii)  et al.
, and so on (et cetera)  , etc.
that is (id est)  i.e.,
about (circa)


viz.,
c. or ca.

vs.
Commonly Misused Abbreviations
Except for the abbreviations of titles, times and dates, acronyms, and some Latin terms,
abbreviations are generally unacceptable in formal writing, which aims for clarity. Unless you
know that an abbreviation is accepted within your discipline, spell out the words. Table 5 lists
some commonly abbreviated words that should be spelled out when used in sentences in a text.
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Table 5.
Commonly Misused Abbreviations
Misused Abbreviations
Word to Use in Text
co.
company
lb.
pound
cm.
centimeter
Sun.
Sunday
Mar.
March
Eng.
England
soc.
sociology
p.
page
chap.
chapter
MD
Maryland
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