Understanding WCAG 2.0

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Info and Relationships:
Understanding SC 1.3.1

1.3.1 Info and Relationships: Information, structure, and relationships conveyed through presentation can be programmatically determined or are available in text. (Level A)

Intent of this Success Criterion

The intent of this Success Criterion is to ensure that information and relationships that are implied by visual or auditory formatting are preserved when the presentation format changes. For example, the presentation format changes when the content is read by a screen reader or when a user style sheet is substituted for the style sheet provided by the author.

Sighted users perceive structure through various visual cues — headings are often in a larger, bold font separated from paragraphs by blank lines; list items are preceded by a bullet and perhaps indented; paragraphs are separated by a blank line; items that share a common characteristic are organized into tabular rows and columns; form fields may be positioned as groups that share text labels; a different background color may be used to indicate that several items are related to each other; words that have special status are indicated by changing the font family and /or bolding, italicizing, or underlining them and so on.

Auditory cues may be used as well. For example, a chime might indicate the beginning of a new section; a change in voice pitch or speech rate may be used to emphasize important information or to indicate quoted text; etc.

When such relationships are perceivable to one set of users, those relationships can be made to be perceivable to all. One method of determining whether or not information has been properly provided to all users is to access the information serially in different modalities.

If links to glossary items are implemented using anchor elements (or the proper link element for the technology in use) and identified using a different font face, a screen reader user will hear that the item is a link when the glossary term is encountered even though they may not receive information about the change in font face. An on-line catalog may indicate prices using a larger font colored red. A screen reader or person who cannot perceive red, still has the information about the price as long as it is preceded by the currency symbol.

Some technologies do not provide a means to programmatically determine some types of information and relationships. In that case then there should be a text description of the information and relationships. For instance, "all required fields are marked with an asterisk (*)". The text description should be near the information it is describing (when the page is linearized), such as in the parent element or in the adjacent element.

There may also be cases where it may be a judgment call about what information should appear in text and what would need to be directly associated, and it may be most appropriate to duplicate some information (for instance, in an HTML table, providing the summary both in the paragraph before the table and in the summary attribute of the table itself). However, wherever possible it is necessary for the information to be programmatically determined rather than providing a text description before encountering the table.

Note: It is not required that color values be programmatically determined. The information conveyed by color cannot be adequately presented simply by exposing the value. Therefore, Success Criterion 1.4.1 addresses the specific case of color, rather than Success Criterion 1.3.1.

Specific Benefits of Success Criterion 1.3.1:

  • This Success Criterion helps people with different disabilities by allowing user agents to adapt content according to the needs of individual users.

  • Users who are blind (using a screen reader) benefit when information conveyed through color is also available in text (including text alternatives for images that use color to convey information).

  • Users who are deaf-blind using braille (text) refreshable displays may be unable to access color-dependent information.

Examples of Success Criterion 1.3.1

Techniques and Failures for Success Criterion 1.3.1 - Info and Relationships

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: The technology provides semantic structure to make information and relationships conveyed through presentation programmatically determinable:

  1. G115: Using semantic elements to mark up structure AND H49: Using semantic markup to mark emphasized or special text (HTML)

  2. G117: Using text to convey information that is conveyed by variations in presentation of text

  3. Separating information and structure from presentation to enable modification of presentation without altering content (future link)

  4. Making information and relationships conveyed through presentation programmatically determinable using the following techniques:

Situation B: The technology in use does NOT provide the semantic structure to make the information and relationships conveyed through presentation programmatically determinable:

  1. G117: Using text to convey information that is conveyed by variations in presentation of text

  2. Making information and relationships conveyed through presentation programmatically determinable or available in text using the following techniques:

Additional Techniques (Advisory) for 1.3.1

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.

Failures for SC 1.3.1

The following are common mistakes that are considered failures of Success Criterion 1.3.1 by the WCAG Working Group.

Key Terms

assistive technology (as used in this document)

hardware and/or software that acts as a user agent, or along with a mainstream user agent, to provide functionality to meet the requirements of users with disabilities that go beyond those offered by mainstream user agents

Note 1: functionality provided by assistive technology includes alternative presentations (e.g., as synthesized speech or magnified content), alternative input methods (e.g., voice), additional navigation or orientation mechanisms, and content transformations (e.g., to make tables more accessible).

Note 2: Assistive technologies often communicate data and messages with mainstream user agents by using and monitoring APIs.

Note 3: The distinction between mainstream user agents and assistive technologies is not absolute. Many mainstream user agents provide some features to assist individuals with disabilities. The basic difference is that mainstream user agents target broad and diverse audiences that usually include people with and without disabilities. Assistive technologies target narrowly defined populations of users with specific disabilities. The assistance provided by an assistive technology is more specific and appropriate to the needs of its target users. The mainstream user agent may provide important functionality to assistive technologies like retrieving Web content from program objects or parsing markup into identifiable bundles.

Example: Examples of assistive technologies that are important in the context of this document include the following:

  • screen magnifiers, and other visual reading assistants, which are used by people with visual, perceptual and physical print disabilities to change text font, size, spacing, color, synchronization with speech, etc. in order to improve the visual readability of rendered text and images;

  • screen readers, which are used by people who are blind to read textual information through synthesized speech or braille;

  • text-to-speech software, which is used by some people with cognitive, language, and learning disabilities to convert text into synthetic speech;

  • voice recognition software, which may be used by people who have some physical disabilities;

  • alternative keyboards, which are used by people with certain physical disabilities to simulate the keyboard (including alternate keyboards that use head pointers, single switches, sip/puff and other special input devices.);

  • alternative pointing devices, which are used by people with certain physical disabilities to simulate mouse pointing and button activations.


rendering of the content in a form to be perceived by users

programmatically determined / programmatically determinable

determined by software from author-supplied data provided in a way that different user agents, including assistive technologies, can extract and present this information to users in different modalities

Example: Determined in a markup language from elements and attributes that are accessed directly by commonly available assistive technology.

Example: Determined from technology-specific data structures in a non-markup language and exposed to assistive technology via an accessibility API that is supported by commonly available assistive technology.


meaningful associations between distinct pieces of content

user agent

any software that retrieves and presents Web content for users

Example: Web browsers, media players, plug-ins, and other programs — including assistive technologies — that help in retrieving, rendering, and interacting with Web content.