WAI: Strategies, guidelines, resources to make the Web accessible to people with disabilities
WAI-ARIA roles, states, and properties are available in a number of machine-readable formats to support validation of content using WAI-ARIA attributes. WAI-ARIA is not finalized, however, so these files are subject to change without notice.
It is not appropriate to use these document types for live content. These are made available only for download, to support local use in development, evaluation, and validation tools. Using these versions directly from the W3C server could cause automatic blockage, preventing them from loading.
If it is necessary to use schemata in content, follow guidelines to avoid excessive DTD traffic. For instance, use caching proxies to avoid fetching the schema each time it is used, or ensure software uses a local cache, such as with XML catalogs.
The taxonomy for WAI-ARIA expressed in RDF.
This module declares the WAI-ARIA attributes as a module that can be included in a modularlized DTD. Note the WAI-ARIA attributes are in no namespace, and the attribute name begins with "aria-" to reduce the likelihood of collision with existing attributes.
This DTD extends XHTML 1.1 and adds the WAI-ARIA state and property attributes to all its elements. In order to provide broader keyboard support, it also adds the tabindex attribute to a wider set of elements.
This is not a formal document type and may be obsoleted by future formal XHTML DTDs that support WAI-ARIA.
Documents written using this XHTML Family markup language can be validated using the above DTD. If a document author wants to faciliate such validation, they can include the following declaration at the top of their document:
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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML+ARIA 1.0//EN"
"http://www.w3.org/WAI/ARIA/schemata/xhtml-aria-1.dtd">
However, note that when this DOCTYPE is present in a document, most user agents treat the document as generic XML rather than HTML. This causes them to be unable to support named character entities defined by the DTD (e.g., ©). Therefore, authors need to avoid use of named entities outside of the predefined entities in XML ([XML], Section 4.6).
To avoid the above problem, authors can omit the above DOCTYPE statement. This causes user agents to treat the document as generic HTML with named character entity support as well as built-in ARIA support. However, it causes user agents to enter "quirks" mode which affects CSS rendering, and causes conformance checkers to fail the document due to the added ARIA attributes.
To avoid the issues of named character entity support and quirks mode, authors can instead use the following generic DOCTYPE declaration for HTML:
<!DOCTYPE html>
However, this still does not guarantee that documents will be validated by conformance checkers.
This module declares the WAI-ARIA attributes as an XML Schema module that can be included in a modularlized schema. Note the WAI-ARIA attributes are in no namespace, and the attribute name begins with "aria-" to reduce the likelihood of collision with existing attributes.
This standalone DTD adds WAI-ARIA state and property attributes to all elements in HTML 4.01, as well as a role attribute. In order to provide broader keyboard support, it also adds the tabindex attribute to a wider set of elements.
The DTD is based on the HTML 4.01 Transitional DTD, and includes all entity references needed to make it a standalone file. This is not an official W3C DTD and should be considered a derivative work of HTML 4.01.
Documents written using this markup language can be validated using the above DTD. If a document author wants to faciliate such validation, they can include the following declaration at the top of their document:
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML+ARIA 1.0//EN"
"http://www.w3.org/WAI/ARIA/schemata/html4-aria-1.dtd">
However, note that when this DOCTYPE is present in a document, most user agents treat the document as generic XML rather than HTML. This causes them to be unable to support named character entities defined by the DTD (e.g., ©). Therefore, authors need to avoid use of named entities outside of the predefined entities in XML ([XML], Section 4.6).
To avoid the above problem, authors can omit the above DOCTYPE statement. This causes user agents to treat the document as generic HTML with named character entity support as well as built-in ARIA support. However, it causes user agents to enter "quirks" mode which affects CSS rendering, and causes conformance checkers to fail the document due to the added ARIA attributes.
To avoid the issues of named character entity support and quirks mode, authors can instead use the following generic DOCTYPE declaration for HTML:
<!DOCTYPE html>
However, this still does not guarantee that documents will be validated by conformance checkers.
The HTML Working Group is incorporating WAI-ARIA into HTML 5. Official support for WAI-ARIA in HTML will be provided in that specification. This DTD is made available only as a bridging solution for applications requiring DTD validation but not using HTML 5.