Minimum Accessibility Requirements
SSU Websites that do not or cannot use SSU's Web templates must meet these minimum requirements described below. The following requirements must be met, unless a manual evaluation using assistive technology shows that not meeting the standard does not cause an accessibility problem.
These requirements meet the CSU Accessible Technology Initiative's Manual Evaluation for compliance with Section 508 and Best Practices.
Syntax Validation
- Pages must use valid HTML 4.x or XHTML 1.x or HTML 5.
- When CSS is used, it must be valid CSS2 or CSS3.
Semantic Validation
- The text of each link must describe where the link goes.
- Links with the same text (on the same page) must go to the same place.
- Headings must be used to reflect the structure of the document.
- Headings must be properly nested by level.
Checkpoint A - Text Equivalents
- Images that convey content must have equivalent alt text.
- Purely decorative images must have empty alt text (alt="").
- Alt text must make sense in the context of the page as spoken.
- Images that convey complex content must have longdesc attributes or equivalent text content elsewhere on the page.
- Text content in images must not disappear when the images are not available.
- Image map area alt text must describe link destinations correctly.
Checkpoint B - Multimedia Equivalents
- All spoken content (audio and video) must have synchronized captions.
Checkpoint C - Color
- All information conveyed by color must also be conveyed by context, markup, graphic coding, or other means accessible to assistive technology.
- The contrast between foreground and background colors must have a luminosity contrast ratio of least 5:1 for both normal vision and color blindness.
Note: For most text, the luminosity contrast ratio should be at least 10:1. - The correct contrast ratio must be maintained when images are not available.
Checkpoint D - Styles
- CSS, font tags or images must not be used to simulate headings or other semantic markup (instead of using semantic markup).
- With all CSS disabled:
- color and font information must be rendered in the browser's default style;
- headings, paragraphs and lists must be obvious and sensible;
- the order of the page content must make sense as read;
- most text (other than logos and banners) must be displayed as text rather than images;
- no content may appear that was not visible before.
Checkpoint E - Server-side Image Maps
- The page must not use server-side image maps.
Checkpoint F - Client-side Image Maps
- If client-side image maps are used, items 3, 4, 7 and 9 above must be done correctly.
- If client-side image maps are used, an accessible, non-graphic alternative to the image map must be available.
- Tables that contain data must use <th> elements for the top row, and/or left column to indicate table headings.
Checkpoint G - Simple Tables
- Tables that use the <th> element must use the scope attribute to mark the scope of the heading (either scope="col" or scope="row").
- Tables that are used for layout only must not use <th> or <thead>.
- Tables that contain data must use the summary attribute to explain the meaning of the table if it is not otherwise evident from context.
Checkpoint H - Complex Tables
- For complex data tables (those in which there is more than one level of header for any column or row):
- each <th> element must contain the id attribute;
- each <td> element must contain a headers attribute that associates it with its column and row headers.
- <thead> and <tbody> elements are used to clarify the table structure.
Checkpoint I - Frames
- If frames are used:
- Each frame must have a meaningful title attribute.
- Each page that uses frames must have equivalent content in a <noframe> for user agents that do not support frames.
Checkpoint J - Flicker
- Page content must not blink, flicker or flash at an unhealthy rate.
Checkpoint K - Text Only
- A page must not have a "Text Only" version unless it is not possible to make the page meet accessibility requirements.
Note: there is no reason today to have separate versions, despite the grudging exception contained in this checkpoint. For quick repair, a text version must contain the same information as the basic page.
Checkpoint L - Scripts
- HTML event handlers must be accessible to both mouse and keyboard users, unless purely decorative.
- All content and functionality generated by scripts (including href="javascript:...") must also be provided to user agents that do not support scripts, unless purely decorative.
- Modern unobtrusive JavaScript must be used in place of older coding techniques - this coding technique does not require a <noscript> to meet accessibility requirements.
Checkpoint M - Plugins & Applets
- Pages that link to or embed content that requires a special reader or plug-in must also link to the reader/plug-in download.
- Special readers or plug-ins linked to (in item 31) must comply with the requirements of Section 508 paragraphs 1194.21(a)-(l), the Subpart B technical standards for software.
- Documents that are presented in commonly-supported formats such as PDF and Word must be constructed so as to be accessible.
Checkpoint N - HTML Forms
- HTML form <input> elements or controls (except buttons) must have an associated and visible <label> element or title attribute.
- All cues for filling out the form (mandatory fields, help boxes, error messages, etc.) must be available to users of assistive technology.
- The tab order to reach the form and tab order between form elements is consistent with the normal order of entering form data.
- Logically related groups of form elements must be identified with the appropriate <fieldset>, <legend> or <caption> elements.
- If placeholder text is used, it must not be redundant or distracting to users of assistive technology.
Checkpoint O - Navigation & Skip Links
- Users must be able to navigate over groups of links, between multiple groups of links, and between sections of page content by means of section headings or visible and audible local links.
Note: Headings are most helpful for users of assistive technology; "skip" links and headings can be used in combination where appropriate.
Checkpoint P - Timed Response
- If a timed response is required, the user must be alerted and given sufficient time to indicate more time is required.
User Validation
- All text (except in banner graphics) must enlarge or shrink in response to browser text size settings.
- When text is enlarged with browser settings, the text must wrap within columns.
- Columns, page elements and text lines must not overlap each other when text is enlarged with browser settings.
- Actual low vision users should not encounter any remaining barriers - if so, they must be fixed.
- Actual blind users should not encounter any remaining barriers - if so, they must be fixed.
- Actual users with other disabilities should not encounter any remaining barriers - if so, they must be fixed.