Types of Abbreviation

What Are the Four Different Types of Abbreviation?

An abbreviation is a shortened version of a written word or phrase used to replace the original. Here are some examples of abbreviations:
  • RAF is short for Royal Air Force.
  • Prof. is short for Professor.
  • CNN is short for Cable News Network.
  • M.O.T. is short for Ministry of Transport.
  • Mr. or Mr is short for Mister.
  • ("Mr." (with a period) is expected in the US. Outside the US, "Mr" is acceptable. There is more on this to come...)
As these examples prove, abbreviations come in different forms.

Table of Contents

  • The Different Types of Abbreviation
  • The Four Different Types of Abbreviation in Detail
  • (1) Acronyms
  • (2) Contractions
  • (3) Initial Abbreviations (or Initialisms)
  • (4) Syllabic Abbreviations
  • Why Abbreviations Are Important
  • Test Time!

The Different Types of Abbreviation

Here is an infographic showing the different types of abbreviations.
types of abbreviation

The Four Different Types of Abbreviation in Detail

Here is more detail on each of the four different types of abbreviation:

(1) Acronyms

An acronym is an abbreviation spoken like a word. For example:
  • DOS
  • (Disk Operating System)
  • (Navy, Army, and Air Force Institutes)
  • (Buy One Get One Free)
Through common usage, a few acronyms have become words in their own rights. Examples include "sonar," "radar," "laser," and "scuba." Nowadays, these are rarely capitalized.

Some acronyms have not yet made a full transition to "recognized word" and can be written with all capital letters or just an initial capital letter (e.g., NATO or Nato). Read more about acronyms.

(2) Contractions

A contraction is a contracted version of a word. (A contraction often includes an apostrophe to replace any missing letters.) For example:
  • You're
  • (In full: You are)
  • Can't
  • (In full: Cannot)
  • Mr.
  • (In full: Mister)
There are two kinds of contraction:
  • A Contraction with an Apostrophe. This type shortens a word or merges two words into one by replacing the missing letter(s) with an apostrophe. For example:
    • don't
    • can't
    • shouldn't
  • A Contraction without an Apostrophe. This type compresses a word. For example:
    • Mr.
    • Revd.
    • Prof.
Read more about contractions. Read more about using apostrophes to replace missing letters. Read more about using periods (full stops) in contractions.

(3) Initial Abbreviations (or Initialisms)

An initialism is an abbreviation whose letters each represent a word. For example:
  • AQI
  • (Air Quality Index)
  • MLRS
  • (Multiple Launch Rocket System)
  • ITV
  • (Independent Television)
Initialisms can be written with or without periods (full stops). The most common practice is to avoid periods. However, when using company names, copy the company's version. Read more about periods (full stops) in abbreviations.

(4) Syllabic Abbreviations

A syllabic abbreviation is an abbreviation formed from the initial syllables of multiple words. For example:
  • Interpol (International Police)
  • INMARSAT (International Maritime Satellite)
  • Gestapo (Geheime Staats Polizei)
  • Comintern (Communist International)

Why Abbreviations Are Important

Here are five good reasons to think a little more carefully about abbreviations.

(Reason 1) Don't use the word "acronym" for an initialism.

The words "acronym" and "abbreviation" are not synonyms (i.e., they do not mean the same thing). Remember that abbreviations like BBC and CNN are not acronyms but initialisms. Acronyms are spoken like words.
  • There is a list of acronyms at the back of the document. wrong cross
  • (This is a common statement made at the start of formal documents. The list at the back is always a list of abbreviations, some of which are acronyms.)
Read more about acronyms.

(Reason 2) Be consistent with periods (full stops).

Initialisms can be written with or without periods. Not using periods is far more common than using them. For example:
  • BBC correct tick
  • (This is the most common convention.)
  • B.B.C. correct tick
  • (This is an acceptable convention. If you adopt it, remain consistent throughout your document.)
Whatever convention you use, be consistent. There is only one ruling that will trump your striving for consistency: If you're writing the name of a company, adopt whatever convention the company uses for itself. Read more about periods in abbreviations.

(Reason 3) Know when to use periods (full stops) with contractions.

Contractions that do not use apostrophes (e.g., "Dr." and "Prof.") are followed by periods in America. Outside America, the guideline is to use a period only if the last letter of the contraction is different from the last letter of the whole word. For example:
  • Dr. correct tick (small American flag)
  • (This version is expected in America. It is also accepted outside America.)
  • Dr correct tick (small British flag)
  • (This version is widely used outside America. No period is required because the last letter of "Dr" and "Doctor" are the same.)
  • Dr wrong cross (small American flag)
  • Prof. correct tick (small American flag) correct tick (small British flag)
  • (This version is expected in America. It is also expected outside America because the last letters of "Prof" and "Professor" are different.)
  • Prof correct tick (small British flag)
  • (This version is accepted outside America.)
Read more about periods with contractions.

(Reason 4) Form the plurals of abbreviation correctly.

The plural of an abbreviation is formed by adding "s." Do not use an apostrophe. For example:
  • RTA > RTAs correct tick
  • (RTA = Road Traffic Accident)
  • SME > SME's wrong cross
  • (SME = Small to Medium Enterprise)
Be aware, however, that the plural of an awkward abbreviation can be formed by adding 's. Generally, this is something to be avoided, but, if the author believes the apostrophe helps readers, it can be added. For example:
  • COS > COS's
  • (COS = Chief of Staff)
  • COS > COS'S
  • (An apostrophe is useful when only capital letters can be used, e.g., in titles.)
Read more forming the plurals of abbreviations.

(Reason 5) Be consistent with writing units of measurement.

When using units such as "mph" or "cm," you can either use a space after the number or not. The choice is yours. However, be consistent throughout your document.
  • 700mph, 99m, 10cm, -4°C correct tick
  • 700 mph, 99 m, 10 cm, -4 °C correct tick
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This page was written by Craig Shrives.