Use conventional abbreviations that readers can easily understand.
The following examples are commonly used abbreviations and all take periods after them:
|Messrs. (for two or more men) as in Messrs. Smith, Jones, and Williams.|
|Esq. (always omit the Mr., Ms. or Mrs. when using Esq. after the name)|
Dates and times may use abbreviations:
- B.C. included in a date as 496 B.C. without a comma.
- A.M., P.M. or AM, PM is acceptable without the periods.
The months in the year follow standard abbreviations: Jan., Feb., Mar. Apr., etc.
Days of the week also follow standard abbreviations: Mon., Tues., Wed., Thurs., Fri., Sat., Sun.
Some familiar abbreviations are acceptable without periods: TV, FBI, USA, YMCA
However, periods are also acceptable with them: OK or O.K.
U.N. and U.S. delegation are customary usage. Note that U.S. serves only as an adjective; write out the United States when it is a noun.
Select scientific phrases also go without periods, especially when combined with numbers:
College degrees are abbreviated and easily recognizable:
- A.B. or B.A.
- D. Litt.
Latin abbreviations used in prose include:
- (exempli gratia, "for example")
- (id est, "that is")
- (et cetera, better written out as "and so forth")
- (videlicet, "that is," "namely")
These abbreviations are followed by commas or colons after the period.
- The FBI discovered three mistakes in its investigation, i.e., failure to follow proper procedures, erroneous record keeping, and unnecessary expenditures.
Abbreviations in research papers are often used with end notes. Among the commonly used ones are:
- c. or ca.
- circa, "about" (c. 1606)
- confer ("bring together" or "compare"); do not use for "see."
- ch. or chs.
- chapter, chapters
- edited by, edition, editor
- et al.
- et alii ("and others"); does not mean "and all"; use after the first author in multiple authorships: Lewis Cunningham et al.
- f., ff.
- and the following page, pages
- l., ll.
- line, lines
- loc. cit.
- loco citato ("in the place cited"); use without page number, when you cite a page previously noted.
- MS., MSS.
- manuscript, manuscripts
- no date given
- no place of publication given
- (not an abbreviation, but a Latin word meaning "throughout the work; here and there") use when a writer makes the same point in many places within a single work; also, use also for statistics compiled from observations and tables scattered through the work.
- p., pp.
- page, pages
- (Latin word meaning "so"; "this is so"; always used in brackets [sic]). Used only within quotations following some misspelling or other detail to show that it really was there, was "so" in the original and that the mistake is not your mistake.
- tr., trans.
- translated by
- vol., vols.
- volume, volumes