Pronounced Abbreviations

        Pronounced Abbreviations                                                                                                                                                                      

Use all capitals and no periods to abbreviate names and titles when the abbreviations are pronounced letter by letter.

Examples: NFL NEA AFL-CIO CBS IRS IRA TV

Use all capitals and no periods for acronyms. Acronyms are abbreviations which have been made into pronounced words.

Examples: OPEC NAFTA NATO BASIC SCUBA

Using abbreviations such as these is fine in standard writing, but it is a good idea to identify the acronym or abbreviation for your audience the first time word by word so that there is no misunderstanding.

Example:He got into trouble because of his involvement in an Individual Retirement Account at work. His IRA went over the limit, and he owed some back taxes.

(Spelling the name out the first time helps just in case, for example, someone were thinking of the Irish Republican Army!)

Business Abbreviations

Abbreviations in business names begin with a capital letter and end with a period except for the ampersand (&).

In formal writing, write out the full name of the business.

The legal abbreviations Inc. and Ltd. may be abbreviated.

Abbreviations of Latin Expressions

Use small letters and periods for most abbreviations of Latin terms. Common Latin expression like those listed here are not normally underlined or italicized. They are usually used in bibliographies, footnotes, lists, and references.

In standard writing, use the English equivalent or write out the whole word.

They are usually underlined or italicized in formal references, notes, and bibliographies.

Abbreviation	Equivalent
c., ca.	circa, about, around
e.g.	for example
et al.	et alii, and the others
etc.	et cetera and so on, note the spelling
et seq.	and the following (usually pages)
f.	and the next page
ff.	and the following pages
i.e.	id est, that is
N.B.	Nota Bene, note well (capitalize)
op.	opus, work (of art)
q.v.	which see
v.	see
v., vs.	versus
viz.	vidilicet, namely

Correct: Geoffrey Chaucer (c. 1343-1399)

Incorrect: Geoffrey Chaucer was born c. 1343.
(Standard sentence, not a reference--write out the word or use the English equivalent.)

Correct: Geoffrey Chaucer was born circa 1343.

Correct: Geoffrey Chaucer was born about 1343.

Abbreviations of Time References

Abbreviations for time read from a clock begin with small letters. Those for months and days of the week begin with capital letters. They all end with a period.

These abbreviations are used in charts, calendars, lists, informal writing, and the like. Spell the words out in standard formal writing.

Clock time: sec. min. hr. (sometimes h.)

Days of the Week: Mon. Tue. (Tues.) Wed. Thu. (Thurs.) Fri. Sat. Sun.

Months: Jan. Feb. Mar. Apr. Aug. Sep. (Sept.) Oct. Nov. Dec.

May, June, and July are not normally abbreviated, though sometimes Jun. and Jul. are used when space is limited to three letters.

A.M. and P.M. may either be written in all capital letters or all lower case, but choose one style and stick with it. B.C, B.C.E., and A.D. are always capitalized. Each letter in all five abbreviations is followed by a period.

These abbreviations may be used in all types of writing but only with numbers or a numerical reference.

If you wish to use B.C., B.C.E., or A.D. in a sentence referring to a century, the abbreviation follows the century.

B.C. and B.C.E. always follow the date; A.D. may either precede or follow a numerical date.

None of these abbreviations are separated by commas.

Incorrect: We will meet in the p.m.
(OK informally; not standard use, no number.)

Correct: We will meet at 1:15 p.m.

Correct: Alexander ruled in the fourth century B.C.
(Abbreviation always follows century reference.)

Correct: Charlemagne was crowned in A.D. 800.

Correct: Charlemagne was crowned in 800 A.D.
(Either way is OK for A.D. and a number.)

Since a.m. means "before noon" and p.m. means "after noon," use no other expression of time of day with them.

Incorrect: He arrived at 10 p.m. in the evening.
(In the evening is redundant)

Correct: He arrived at 10 p.m.

Correct: He arrived at 10 in the evening.

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Abbreviations of Units of Measurement

Abbreviations for most units of measurements use small letters and periods. The few exceptions that use capital letters are noted below. Temperature abbreviations use capitals because they come from proper nouns. Measures of mass or weight of types of tons are usually capitalized when abbreviated.

Abbreviations for metric units, including temperatures (Kelvin or Celsius), do not end with periods. Non-metric units with "per" (such as "miles per hour") usually do not take periods, either.

Temperature abbreviations are used in all types of writing. Other abbreviations of measurements are limited to lists, charts, technical writing, and informal writing. In standard formal English, they are spelled out.

If you spell out the number, spell out the unit of measurement.

There is no need to add an s to an abbreviation to show a plural. This is sometimes done in advertising ("3 lbs. for a dollar"), but it is not necessary.

English Unit Abbreviations

Abbreviation	Unit of Measurement
bbl.	barrel
cu.	cubic
doz.	dozen
F., F	Fahrenheit
fl. oz.	fluid ounce
ft.	foot
gal.	gallon
gr.	grain
gr., gro.	gross
in.	inch
k., kt.	karat
k., kt.	knot
lb.	pound
LT, L.T.	long ton
mi.	mile
mph	miles per hour
n.m.	nautical miles
oz.	ounce
pt.	pint
qt.	quart
sq.	square
rpm	revolutions per minute
T., T	ton
T.	tablespoon in some cookbooks
t.	teaspoon in some cookbooks
tbsp.	tablespoon
tsp.	teaspoon
yd.	yard

The single hatch mark ' can stand for foot or a geographical minute (a minute of longitude or latitude). The double hatch mark " can stand for inch or geographical second (a second of longitude or latitude). So 5'6" would mean five feet, six inches. 42°24'54" N. would mean 42 degrees, 24 minutes, 54 seconds north.

Metric Abbreviations

Abbreviation	Unit of Measurement
b	bit
B	byte
C	Celsius, Centigrade
cc or cm³	cubic centimeter (cm³ is standard)
cm	centimeter
G,GB	gigabyte (GB is standard)
g, gr	gram (g is standard)
ha	hectare
K	Kelvin
K, KB	kilobyte (KB is standard)
kg	kilogram
kl	kiloliter
km	kilometer
l	liter
m	meter
M, MB	megabyte (MB is standard)
mcg or µg	microgram ( µg is standard)
mg	milligram
ml	milliliter
mm	millimeter
MT	metric ton
t, T	metric ton
w, W	watt (W is standard)
kw, kW	kilowatt (kW is standard)
kwh, kWh	kilowatt-hour (kWh is standard)

Since the metric system uses standard prefixes, you can easily figure out most other metric abbreviations; for example, cl would be centiliter.

The Greek letter µ (mu) is often used to show the prefix micro, especially in scientific publications. For example, µg would be the same as mcg, and µl would be microliter. When by itself, µ stands for micron. mµ means millimicron, and µµ means micromicron (a millionth of a micron).

The prefix nano means "billionth," and is usually represented by the letter n, as in ns for nanosecond.

To abbreviate most square and cubic units in the metric system, add the exponent ² for square and the exponent ³ for cubic. For example, m² means square meter, and mm³ means cubic millimeter. If you use this notation, use it consistently: Use cm³ rather than cc for cubic centimeter.

In standard scientific notation, the word per is represented by a virgule. So km/h is kilometers per hour.

For international standards including abbreviations for very tiny and very large units, see http://physics.nist.gov/cuu/Units/ or http://physics.nist.gov/cuu/Units/checklist.htm.

Abbreviations with Names and Titles of People

Use the full name in standard writing unless the person uses an initial as part of his or her name. Initials may be used in lists and addresses if appropriate.

Correct: George Smith

Correct, only in list or address: G. Smith

Correct: Robert E. Lee
(The initial is fine here because that is the name he went by.)

Social titles before a proper name are capitalized. All but Miss and Master are abbreviated and end with a period.

Social titles: Mr. Master Mrs. Miss Ms.
Mlle. Mme. M. Messrs. (Plural of Mr. or M.)
Mmes. (Plural of Mrs., Ms., Mme.)

Those social titles that are abbreviated are abbreviated only in front of names. 

Correct: Mr. Smith is not at home.

Incorrect: You'd better listen, Mr.
(Mr. is not in front of name; do not abbreviate.)

Correct: You'd better listen, Mister.

Abbreviations of Position or Rank

There are a number of common titles of position and rank which are abbreviated. Except for Dr., they are used only before a person's full name (i.e., at least first and last names); otherwise, the title is spelled out.

Correct: Sgt. Alvin York   Fr. Robert Drinan
Prof. William Alfred    Dr. Milton Friedman

Incorrect: Sgt. York    Fr. Drinan    Prof. Alfred
(Abbreviated without first name or initial.)

Correct: Sergeant York    Father Drinan
Professor Alfred   Dr. Friedman
(Dr. is OK to abbreviate with a last name only.)

Practice for internal correspondence within military commands may differ.

Abbreviations of position and rank include the following.

Professional: Dr.    Atty.   Prof. Hon.

Religious: Rev.    Fr.   Msgr.   Sr.(Sister)   Br.(Brother)   St.

Political: Pres.    Supt.    Rep.    Sen.    Gov.   Amb.    Treas.  Sec.

Military: Pvt.   Cpl.   Spec.   Sgt.   Ens.   Adm.    Maj.    Capt.
Cmdr. (or Cdr.)    Lt.   Lt. Col.   Col.    Gen.

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Abbreviations After a Name

Abbreviations after a name--such as Jr., Sr., and academic titles--are set off by commas. They begin with a capital letter and end with a period.

Do not use the abbreviations unless they follow the name.

Correct: William F. Buckley, Jr.    Walter Judd, M.D.

Incorrect: The average M.D. sees forty patients day.
(Does not follow name)

Correct: The average medical doctor sees forty patients a day.

In a full sentence, each abbreviation after a name is set off by a comma both before and after. No comma is needed at the end if the sentence ends with the abbreviation.

Correct: The Hon. Rep. Walter Judd, M.D., represented a Minnesota district in the U.S. Congress.

See also Commas with Titles

Abbreviations for Geographical Terms

Abbreviations for geographical terms before or after a proper noun begin with a capital letter and end with a period.

Abbreviations for geographical terms are used only in addresses, lists, charts, and maps. They should be spelled out in standard and formal writing.

Common geographical abbreviations:

Ave.    Is.    Prov.

Apt.    L. (Lake)    RR. or R.R.

Blvd.    Mt.    Rd.

Bldg.    Nat. or Natl.    Rt. or Rte.

Co. (County)    Pk.    Sq.

Dr. (Drive)    Pt.    St. (Street, State)

Ft.    Pen. (Peninsula)    Terr.

The abbreviation Wy. can stand for Way, but is seldom used because it is short and it can be confused with the abbreviation for the state of Wyoming. More commonly it is part of the abbreviation of a compound word which includes way such as Hwy. for Highway, Fwy. for Freeway, or Pkwy. for Parkway.

See also state and province abbreviations.

Abbreviations for States and Provinces

Traditional abbreviations for states and provinces begin with a capital letter and end with a period.

Except for the abbreviation D.C. when it follows Washington, which may be used at any time, use the abbreviations for states and provinces only in lists, maps, charts, addresses, and informal writing.

Avoid abbreviations for states, provinces, and countries in formal writing--the exceptions are the relatively long U.S., U.S.A., U.S.S.R., and C.I.S. which may be used at any time.

The two-letter postal service abbreviations are all capitals with no periods. They are not set apart by commas. They are used only with addresses on letters, envelopes, and packages to be mailed.

Correct: P.O. Box 203
Shelton, Conn., 06484
(In an address)

Correct: P.O. Box 203
Shelton CT 06484
(In an address)

Incorrect: He works in Shelton, Conn.
(Standard sentence, do not abbreviate.)

Correct: He works in Shelton, Connecticut.

Correct only because it is informal: Was it really the O'Leary's cow that made Chicago, Ill.?

U.S. State Abbreviations
(Canadian provinces follow this list.)

State/Territory	Traditional	Postal
Alabama	Ala.	AL
Alaska	Alaska	AK
Arizona	Ariz.	AZ
Arkansas	Ark.	AR
American Samoa		AS
California	Cal., Calif.	CA
Colorado	Col., Colo.	CO
Connecticut	Conn.	CT
Delaware	Del.	DE
District of Columbia	D.C.	DC
Fed. States of Micronesia		FM
Florida	Fla.	FL
Georgia	Ga.	GA
Guam	Guam	GU
Hawaii	Hawaii, H.I.	HI
Idaho	Ida., Id., I.	ID
Illinois	Ill.	IL
Indiana	Ind.	IN
Iowa	Iowa, Ia.	IA
Kansas	Kan., Kans.	KS
Kentucky	Ken., Ky.	KY
Louisiana	La.	LA
Maine	Me.	ME
Maryland	Md.	MD
Marshall Islands	Marshall Is.	MH
Massachusetts	Mass.	MA
Michigan	Mich.	MI
Minnesota	Minn.	MN
Mississippi	Miss.	MS
Missouri	Mo.	MO
Montana	Mont.	MT
Nebraska	Neb., Nebr.	NE
Nevada	Nev.	NV
New Hampshire	N.H.	NH
New Jersey	N.J.	NJ
New Mexico	N.M., N.Mex.	NM
New York	N.Y.	NY
North Carolina	N.C.	NC
North Dakota	N.D., N.Dak	ND
Northern Marianas	N. Marianas	MP
Ohio	Ohio, O.	OH
Oklahoma	Okla., Ok.	OK
Oregon	Ore.	OR
Pennsylvania	Penna., Penn., Pa.	PA
Puerto Rico	P.R.	PR
Rhode Island	R.I.	RI
South Carolina	S.C.	SC
South Dakota	S.D., S.Dak.	SD
Tennessee	Tenn.	TN
Texas	Tex.	TX
Utah	Utah, Ut.	UT
Vermont	Vt.	VT
Virginia	Va.	VA
(U.S.) Virgin Islands	U.S.V.I., V.I.	VI
Washington	Wash.	WA
West Virginia	W.Va.	WV
Wisconsin	Wis., Wisc.	WI
Wyoming	Wyo.	WY
Armed Forces, the Americas	USAFA.	AA
Armed Forces, Europe	USAFE	AE
Armed Forces, Pacific	USAFP	AP

Canadian Provinces

Province	Traditional	Postal
Alberta	Alta.	AB
British Columbia	B.C.	BC
Manitoba	Man.	MB
New Brunswick	N.B.	NB
Newfoundland and Labrador	N.F.	NL
Northwest Territories	N.W.T.	NT
Nova Scotia	N.S.	NS
Nunavut		NU
Ontario	Ont.	ON
Prince Edward Island	P.E.I.	PE
Québec	P.Q., Qué.	QC
Saskatchewan	Sask.	SK
Yukon Territory	Yuk., Y.T.	YT