USE STANDARD ABBREVIATIONS

Abbreviations of titles like Mr., Ms., Dr., Rev., and Prof. before names are common in documents, as are abbreviations like Jr., MD, DDS, and PhD after names.

The abbreviations a.m. and p.m. (meaning “morning” and “afternoon”), BC and AD (for “before Christ” and “anno Domini”) or BCE and CE (“before the common era” and “common era”), and ºF and ºC (“degrees Fahrenheit” and “degrees Celsius”) are in standard use in references to specific times, years or periods, and temperatures:

10:00 a.m.

the sixth century BC (or BCE)

AD 78 (or 78 CE)

70ºF (or 21ºC)

Few other abbreviations, apart from acronyms, belong in academic and business documents. However, abbreviations like Mon. and Tues., Jan. and Feb., St. and Rd., and m.p.h. are fine in tables and other places where space is limited.

Use the postal abbreviations for states (AL, AR, and so on) in mailing addresses and lists of APA references but spell out state names elsewhere. If you use abbreviations, use them consistently.

Do not use texting abbreviations like btw and YOLO in formal writing.

USE ACRONYMS TO SIMPLIFY AND CLARIFY

Acronyms are abbreviations made up of the initial letters of words. With a few exceptions, they are written in all caps without periods: AAA, HMO, ISP, USPS. A few acronyms, like U.S. and U.N., are typically written with periods after the initials to keep readers from being tempted to read them as words. Check a dictionary or an organization’s Web site if you have doubts about how to write an abbreviation.

To introduce an acronym, give the full name immediately followed by the acronym in parentheses. When giving the words the acronym stands for, you don’t have to capitalize them merely because they are capitalized in the acronym:

The convention of introducing acronyms in parentheses is intended to alert readers that from then on you will be using the acronym instead of the name. Therefore, include the acronym only if you plan to use it later in your document.

If you use the acronym just once or twice, consider whether your writing might be more readable without the acronym. You can either repeat the full name or use a generic phrase, like “the association” or “the interface.”

If you think that a particular acronym will be familiar to readers and feel that it needs no introduction — for instance, DNA, FBI, and NASA — you may use the acronym without writing out the full name the first time you refer to the thing or organization.