Appropriate Abbreviations

Punctuating Abbreviations

Most abbreviations of single words require periods, as in these examples:

vols.
Jan.
Mr.

Initials and acronyms do not require periods. Consider the following examples:

HBO
AFL-CIO
IRS
CARE
NATO
MADD

Use periods or none at all in technical terms, as is shown in these examples:

m.p.g. or mpg
rpm or r.p.m.

Capitalizing Abbreviations

Use capitals in abbreviations if the words are capitalized when written out, as in these examples:

GM (General Motors)
IRS (Internal Revenue Service)
lb. (pound)
min. (minute)

Always capitalize A.D. and B.C. (also B.C.E.). You can use either A.M. and P.M. or a.m. and p.m. Whichever form you use, be consistent.

Use Appropriate Abbreviations

Abbreviate titles only when they precede a first name. The following examples correctly abbreviate titles:

Pres. George Bush
Sen. Hillary Clinton

Write out any unfamiliar term the first time you use it and provide the abbreviation you will use in the rest of the essay in parentheses. Here is an example:

The Strategic Defense Initiative (SDI) is the president’s new defense proposal.

Also, be sure to use correct Latin abbreviations. Here are some examples of common Latin abbreviations:

i.e. (id est means “that is”)
e.g. (exempli gratia means “for example”)
et al. (et alia means “and others”)

In most writing, use the English versions of Latin terms and avoid using the abbreviation etc. Instead, use specific words or replace etc. with and others, and so on, or among others.

Which sentence is correct? Our flight was supposed to arrive at 7:30 PM, but because of bad weather, mechanical issues, etc., we didn’t arrive until 7:30 am. Because my mother is a travel writer, the IRS allows her to deduct all her travel expenses, for example hotel costs, airfare, and dining expenses, on her tax return.