Abbreviation Rules

Important notes:

  • Saving space using an abbreviation is less important than clarity in writing. Keep your audience in mind. Spell out a term if the abbreviation may confuse your readers.
  • Acronyms (like NASA) and initialisms (like MLA) generally need to be spelled out (defined) when used the first time. EX: I couldn't believe The Ohio State University (OSU) played so well this year.
  • For plural abbreviations, use only an -s and not 's. EX: I lost all 477 DVDs.

Acceptable Abbreviations

Titles before names: I took Dr. Smith's biology class last semester.
The bill was introduced by Sen. Brownberry.
I enjoyed Mrs. Smith's cooking class.
Titles that appear after names: I had heard of Benjamin Spock, M.D.
I felt the need to call Jim Jones, Jr.
Familiar institutions: IBM, CIA, YMCA, FBI, NASA, etc.
Familiar objects commonly abbreviated DVDs, VCR, etc.
Examinations and diplomas I need to take the SAT this weekend.
He received his GED last month.
Time: We met at 3:00 p.m. or (PM).
Dollar sign and percent sign: The bet cost me $2,000.00.
I was 95% sure that I was going to win the bet.


Unacceptable Abbreviations
Titles not attached to specific names: He went to the doctor twice last week.
Names of countries: USA, US, CAN, etc.
Names of cities and states: NYC, LA, OH, KS, NJ, etc.
Months and days of the week: Sept, Oct, Tues, Wed, etc.
Units of measure (when not with numbers): ln, cm, ml, etc.
Courses of study: Eng, bio, chem, soc, etc.
Street signs: St., Ln., Ct., Blvd., Ave., etc.
Miscellaneous symbols: &, +, #, @
Miscellaneous space-saving expressions: We read chap. 4 last night.
We need to be thru chapter 4 by tomorrow.
My two bros. were at the party with me.
I bought misc. presents this weekend.

One good rule to keep in mind: If in doubt, spell it out!