Link Rules

Link text should be meaningful when taken out of context; therefore, links that point to different URIs should have different text contents.

Implementation Notes

• The text content of a link can be hidden to make the link that might otherwise appear confusing to screen reader users unique and meaningful by using the following techniques:
  1. Include span or other element within the link to hide additional text content.
  2. Define alt attribute content for an img or area element.
• The effective link text of links that contain images will include the alt attribute content, in the order of appearance in the document of the images, in addition to the text content of the link.
• Automated validators will remove common default file names from a URI for the purpose of comparison, but maintain any additional URI information that follows the default file name. Examples of default file names are:
  1. index.* (i.e. index.html, index.htm, index.php, etc)
  2. default.* (i.e. default.html, default.htm, default.asp, etc)

An image that is the entire content of a link should be at least 16x16 pixels in size.

The text content of a link should be at least 4 characters in length when rendered graphically.

For links that include an img element and text content, the alt attribute content of the img element should not repeat the text content of the link. Images that are the used as icons to help users identify the purpose of a link should have their alt attribute set to empty or be included in the graphical rendering as a CSS background image.

The first link on a page should be a skip navigation link that contains the word "skip" and the href attribute should point to an internal destination. The skip navigation link should be visible to all users when the link has focus and must comply with other link rules.

Implementation Notes

• Many accessibility requirements, including the Illinois Information Technology Accessibility Act, require the use of the skip navigation link, but there is a disagreement about the utility of skip navigatin link when heading (h1-h6) markup is properly used to indicate the structure of content on the page. Therefore, the presence of the link on a web resource will result in the web resource satisfying this requirement ("Pass") while the absence of the link will only cause "Check"; the authors can then judge whether they need to include the skip navigation link in their resources.

The target of internal links need to include a tabindex attribute with the value set to "-1". This is required for Internet Explorer to move keyboard focus when the internal link is activated.

Small links should not be placed close together.