Understanding WCAG 2.0

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Unusual Words:
Understanding SC 3.1.3

3.1.3 Unusual Words: A mechanism is available for identifying specific definitions of words or phrases used in an unusual or restricted way, including idioms and jargon. (Level AAA)

Intent of this Success Criterion

Certain disabilities make it difficult to understand nonliteral word usage and specialized words or usage. Certain disabilities make it difficult to understand figurative language or specialized usage. Providing such mechanisms is vital for these audiences. Specialized information intended for non-specialist readers is encouraged to satisfy this Success Criterion, even when claiming only Single-A or Double-A conformance.

Specific Benefits of Success Criterion 3.1.3:

This Success Criterion may help people with cognitive, language and learning disabilities who:

  • have difficulty decoding words

  • have difficulty understanding words and phrases

  • have difficulty using context to aid understanding

It would also help people with visual disabilities who:

  • lose context when zoomed-in with a screen magnifier

Examples of Success Criterion 3.1.3

Related Resources

Resources are for information purposes only, no endorsement implied.

Note: The inclusion of a product or vendor name in the list below does not constitute an endorsement by the Web Content Accessibility Guidelines Working Group or the Web Accessibility Initiative of the World Wide Web Consortium. This list is provided simply for convenience and to give users an idea of what resources may be available

Techniques and Failures for Success Criterion 3.1.3 - Unusual Words

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. However, it is not necessary to use these particular techniques. For information on using other techniques, see Understanding Techniques for WCAG Success Criteria, particularly the "Other Techniques" section.

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 word or phrase has a unique meaning within the Web page:

  1. G101: Providing the definition of a word or phrase used in an unusual or restricted way for the first occurrence of the word or phrase in a Web page using one of the following techniques:

  2. G101: Providing the definition of a word or phrase used in an unusual or restricted way for each occurrence of the word or phrase in a Web page using one of the following techniques:

Situation B: If the word or phrase means different things within the same Web page:

  1. G101: Providing the definition of a word or phrase used in an unusual or restricted way for each occurrence of the word or phrase in a Web page using one of the following techniques:

Additional Techniques (Advisory) for 3.1.3

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 markup and visual formatting to help users recognize words that have special meaning (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)

  • Providing a sign language dictionary to help users who are deaf find the necessary definitions (future link)

  • Providing a mechanism for finding definitions for all words in text content (future link)

  • Providing a mechanism to determine the meaning of each word or phrase in text content (future link)

  • Avoiding unusual foreign words (future link)

  • Using a series of dictionaries in cascading fashion to provide meanings (future link)

Common Failures for SC 3.1.3

The following are common mistakes that are considered failures of Success Criterion 3.1.3 by the WCAG Working Group.

(No failures currently documented)

Key Terms


phrase whose meaning cannot be deduced from the meaning of the individual words and the specific words cannot be changed without losing the meaning

Note: idioms cannot be translated directly, word for word, without losing their (cultural or language-dependent) meaning.

Example 1: In English, "spilling the beans" means "revealing a secret." However, "knocking over the beans" or "spilling the vegetables" does not mean the same thing.

Example 2: In Japanese, the phrase "さじを投げる" literally translates into "he throws a spoon," but it means that there is nothing he can do and finally he gives up.

Example 3: In Dutch, "Hij ging met de kippen op stok" literally translates into "He went to roost with the chickens," but it means that he went to bed early.


words used in a particular way by people in a particular field

Example: The word StickyKeys is jargon from the field of assistive technology/accessibility.


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.

used in an unusual or restricted way

words used in such a way that requires users to know exactly which definition to apply in order to understand the content correctly

Example: The term "gig" means something different if it occurs in a discussion of music concerts than it does in article about computer hard drive space, but the appropriate definition can be determined from context. By contrast, the word "text" is used in a very specific way in WCAG 2.0, so a definition is supplied in the glossary.