English punctuation and capitalization rules for abbreviations vary widely because those rules frequently change. Moreover, American and British English differ in the use of periods with names and titles of people. Therefore, you should think of the “rules” for abbreviations as guidelines, not absolutes. Always make sure that the abbreviations you use are consistent with the style guide for your company or field of work.

In our previous two lessons we’ve covered we covered general guidelines for abbreviations, the titles of people, dates and times, and familiar terms that you can safely abbreviate. This week we’ll finish up our abbreviation lessons with postal codes, common Latin abbreviations, and words that you should generally avoid abbreviating.

Postal Abbreviations

The states of the United States and the provinces of Canada have official two-letter postal code abbreviations. These abbreviations are written in capital letters and without spaces and should be used for addresses only. In other situations, write the entire name of a state or province.

The United States has 50 states (plus territories and the District of Columbia) and Canada has 10 provinces, so the following list provides only a small sample:

State/Province	Postal Code Abbreviation
Georgia	GA
California	CA
New York	NY
Alberta	AB
British Columbia	BC
Ontario	ON

Latin Abbreviations

Certain fields, such as academia, expect or require the use of specific Latin abbreviations. Outside of such fields, it is better to use Latin abbreviations sparingly, if at all.

Abbreviation	Latin Phrase	English Equivalent
ca	circa	approximately
cf.	confer	compare
e.g.	exempli gratia	for example
et al.	et alii	and others
etc.	et cetera	and so on
i.e.	id est	that is
vs.	versus	againstopposing

 

Words You Shouldn’t Abbreviate

Avoid abbreviating the following types of words in formal writing unless you are working with a style guide that indicates otherwise.

Units of measure:

Correct: The distance from Atlanta to Macon is about 84 miles or approximately 135 kilometers

Incorrect: The distance from Atlanta to Macon is about 84 mi. or approximately 135 km.

 

Geographical names (except as part of a mailing address):

Correct: James lives in Marietta, Georgia.

Incorrect: James lives in Marietta, GA.

 

Names of days, months, and holidays:

Correct: The SAT class begins on Monday, September 18.

Incorrect: The SAT class begins on Mon., Sept. 18.

 

Parts of a business name and divisions of a business:

Correct: He works in the Quality Assurance Department of Big Company Limited.

Incorrect: He works in the Quality Assurance Dept. of Big Company Ltd.

Parts of the name of a school or the name of a specific subject:

Correct: She graduated from Georgia State University, where she majored in computer science.

Incorrect: She graduated from Georgia State Univ., where she major