Understanding WCAG 2.0

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Understanding SC 3.1.4

3.1.4 Abbreviations: A mechanism for identifying the expanded form or meaning of abbreviations is available. (Level AAA)

Intent of this Success Criterion

The intent of this Success Criterion is to ensure that users can access the expanded form of abbreviations.

Specific Benefits of Success Criterion 3.1.4:

This Success Criterion may help people who:

  • have difficulty decoding words;

  • rely on screen magnifiers (magnification may reduce contextual cues);

  • have limited memory;

  • have difficulty using context to aid understanding.

Abbreviations may confuse some readers in different ways:

  • Some abbreviations do not look like normal words and cannot be pronounced according to the usual rules of the language. For example, the English word "room" is abbreviated as "rm," which does not correspond to any English word or phoneme. The user has to know that "rm" is an abbreviation for the word "room" in order to say it correctly.

  • Sometimes, the same abbreviation means different things in different contexts. For example, in the English sentence "Dr. Johnson lives on Boswell Dr.," the first "Dr." is an abbreviation for "Doctor" and the second instance is an abbreviation for the word "Drive" (a word that means "street"). Users must be able to understand the context in order to know what the abbreviations mean.

  • Some acronyms spell common words but are used in different ways. For example, "JAWS" is an acronym for a screen reader whose full name is "Job Access with Speech." It is also a common English word referring to the part of the mouth that holds the teeth. The acronym is used differently than the common word.

  • Some acronyms sound like common words but are spelled differently. For example, the acronym for Synchronized Multimedia Integration Language, S M I L, is pronounced like the English word "smile."

It would also help people with visual disabilities who:

  • Lose context when zoomed-in with a screen magnifier

Examples of Success Criterion 3.1.4

Related Resources

Resources are for information purposes only, no endorsement implied.

Techniques and Failures for Success Criterion 3.1.4 - Abbreviations

Each numbered item in this section represents a technique or combination of techniques that the WCAG Working Group deems sufficient for meeting this Success Criterion. The techniques listed only satisfy the Success Criterion if all of the WCAG 2.0 conformance requirements have been met.

Sufficient Techniques

Instructions: Select the situation below that matches your content. Each situation includes techniques or combinations of techniques that are known and documented to be sufficient for that situation.

Situation A: If the abbreviation has only one meaning within the Web page:

  1. G102: Providing the expansion or explanation of an abbreviation for the first occurrence of the abbreviation in a Web page using one of the following techniques:

  2. G102: Providing the expansion or explanation of an abbreviation for all occurrences of the abbreviation in a Web page using one of the following techniques:

Situation B: If the abbreviation means different things within the same Web page:

  1. G102: Providing the expansion or explanation of an abbreviation for all occurrences of abbreviations in a Web page using one of the following techniques:

Additional Techniques (Advisory) for 3.1.4

Although not required for conformance, the following additional techniques should be considered in order to make content more accessible. Not all techniques can be used or would be effective in all situations.

  • Using unique abbreviations in a Web page (future link)

  • Using visual formatting to help users recognize abbreviations (future link)

  • Providing access to a talking dictionary to support users who might have difficulty decoding written definitions (future link)

  • Providing a voice-enabled dictionary search so that users who have difficulty typing or spelling can speak the word whose definition they need (future link)

Common Failures for SC 3.1.4

The following are common mistakes that are considered failures of Success Criterion 3.1.4 by the WCAG Working Group.

(No failures currently documented)

Key Terms


shortened form of a word, phrase, or name where the abbreviation has not become part of the language

Note 1: This includes initialisms and acronyms where:

  1. initialisms are shortened forms of a name or phrase made from the initial letters of words or syllables contained in that name or phrase

    Note 1: Not defined in all languages.

    Example 1: SNCF is a French initialism that contains the initial letters of the Société Nationale des Chemins de Fer, the French national railroad.

    Example 2: ESP is an initialism for extrasensory perception.

  2. acronyms are abbreviated forms made from the initial letters or parts of other words (in a name or phrase) which may be pronounced as a word

    Example: NOAA is an acronym made from the initial letters of the National Oceanic and Atmospheric Administration in the United States.

Note 2: Some companies have adopted what used to be an initialism as their company name. In these cases, the new name of the company is the letters (for example, Ecma) and the word is no longer considered an abbreviation.


process or technique for achieving a result

Note 1: The mechanism may be explicitly provided in the content, or may be relied upon to be provided by either the platform or by user agents, including assistive technologies.

Note 2: The mechanism needs to meet all success criteria for the conformance level claimed.