Data Table Rules

HTML Markup Details

table element
The table element is the container for tabular data markup.
caption element
The caption element is defined in HTML to provide a visible title for a table, but it has not been widely used by developers and therefore assistive technologies do not support it.
summary attribute
The summary attribute, defined in the table element, should describe the content of the table or the conclusion the author intends to convey through the data in the table. Assistive technologies use the summary attribute as the effective title for a data table. The use of the summary attribute should be restricted to data tables and should not be used on layout tables. If more than one data table appears on a page, the summary attribute content should be unique to help screen readers users understand how the content of the two tables is different.
h2 and other heading elements
Heading elements can be used to identify the purpose of a data table and provide a mechanism to navigate to the table.
th and td elements
The th element represents header cells and the td element represents data cells.
id attribute
The id attribute, defined for th elements, should uniquely identify each header cell. This id is used in conjunction with the headers attribute of td elements to indicate headers for a particular data cell.
headers attribute
The headers attribute, defined for td elements, should point to the id of th elements that are the header cells for the data cell.
scope attribute
The scope attribute, defined for td and th elements, is not used by assistive technologies to improve accessibility.

Definitions

Data Table
Contains at least 2 rows and 2 columns, and
Contains at least one of the following:
  1. summary attribute on the table element
  2. caption element
  3. thead element
  4. th element
  5. td element that contains a scope or headers attribute.
Complex Data Table
Satisfies all the requirements of data table detecton, and
Contains at least one of the following:
  1. tr element with a td or th element with rowspan or colspan attribute with a value > 1
  2. tr element that contains both td elements AND more than one th element
  3. thead element that contains more than one tr element
  4. Two or more tr elements that contain only th elements
  5. A tr element with a td or th element with headers attribute that contains more than two idrefs

Accessibility Evaluation Rules

no. Testing Description Implementation
FAE Firefox
Accessibility
Extension
1 Fail/Pass

For each data table, the first cell in each column must be a th element, and each row must contain at least one th element.

1.0 1.5
2 Fail/Pass

Each data table must have a nonempty summary attribute.

Implementation Notes

  • The intent of this rule is to help web developers become aware of using the summary attribute to describe the contents of data tables and any conclusions the author was trying to convey from including the data table in the page.
1.0 1.5
3 Fail/Pass

Each th element in a complex data table must have ad id attribute whose value is unique relative to all ids on the page.

1.0 1.5
4 Fail/Pass

Each td element in a complex data table must have a headers attribute that references the id attributes of associated th elements.

1.0 1.5
5 Warning/Pass

The summary attribute value for each data table on a page should be unique.

1.0 1.5

FAE Rule Implemetation

Illinois Functional Accessibility Evaluator 1.0
The Illinois Functional Accessibility Evaluator is a web based tool to help developers evaluate web resources for the use of the iCITA HTML best practices.
Web interface cannot currently analyze content generated dynamically with javascript.
Illinois Firefox Accessibility Extension
The Illinois Firefox Accessibility Extension is a Firefox add-in that is designed to identify accessibility features for both static and dynamically generated html content.
Useful for identifying the location of specific accessibility problems for failures and warnings indentified in FAE reports.
Create FAE reports for a page that uses javascript to generate page content with the FAE DHTML Report feature.