HTML and CSS Reference
Table C-1 (continued)
WCAG 2.0 Guidelines
Guideline 2.2 Enough Time: Provide users enough time to read and use content.
2.2.1 Timing Adjustable: The user should be able to easily change each time limit that is set
by the content.
2.2.2 Pause, Stop, Hide: The user should be able to pause, stop, or hide moving, blinking,
scrolling, or auto-updating information.
2.2.3 No Timing: Timing is not an essential part of the event or activity presented by the
content, except for noninteractive synchronized media and real-time events.
2.2.4 Interruptions: Interruptions can be postponed or suppressed by the user, except
interruptions involving an emergency.
2.2.5 Re-authenticating: When an authenticated session expires, the user can continue the
activity without loss of data after re-authenticating.
Guideline 2.3 Seizures: Do not design content in a way that is known to cause seizures.
2.3.1 Three Flashes or Below Threshold: Web pages do not contain anything that flashes
more than three times in any one second period, or the flash is below the general flash and
red flash thresholds.
2.3.2 Three Flashes: Web pages do not contain anything that flashes more than three
times in any one second period.
Guideline 2.4 Navigable: Provide ways to help users navigate, find content, and determine
where they are.
2.4.1 Bypass Blocks: A mechanism is available to bypass blocks of content that are repeated
on multiple Web pages.
2.4.2 Page Titled: Web pages have titles that describe topic or purpose.
2.4.3 Focus Order: If a Web page can be navigated sequentially and the navigation sequences
affect meaning or operation, focusable components receive focus in an order that preserves
meaning and operability.
2.4.4 Link Purpose (In Context): The purpose of each link can be determined from the link
text alone or from the link text together with its programmatically determined link context,
except where the purpose of the link would be ambiguous to users in general.
2.4.5 Multiple Ways: More than one way is available to locate a Web page within a
set of Web pages except where the Web Page is the result of, or a step in, a process.
2.4.6 Headings and Labels: Headings and labels describe topic or purpose.
2.4.7 Focus Visible: Any keyboard operable user interface has a mode of operation where
the keyboard focus indicator is visible.
2.4.8 Location: Information about the user's location within a set of Web pages is available.
2.4.9 Link Purpose (Link Only): A mechanism is available to allow the purpose of each
link to be identified from link text alone, except where the purpose of the link would be
ambiguous to users in general.
2.4.10 Section Headings: Section headings are used to organize the content.
Principle 3: Understandable—Information and the operation of user interface must be
Guideline 3.1 Readable: Make text content readable and understandable.
3.1.1 Language of Page: The default human language of each Web page can be
3.1.2 Language of Parts: The human language of each passage or phrase in the content
can be programmatically determined except for proper names, technical terms, words of
indeterminate language, and words or phrases that have become part of the vernacular of the
immediately surrounding text.