From Htmlpedia

HTML Tidy: Accessibility warnings

HTML Tidy has the possibility to check the accessibility of a HTML page following the 3 levels defined in WAI.

List of the Accessiblity warnings

Error id	Link to the error description (en-US)
access_1.1.1.1	Access: [1.1.1.1]: <img> missing 'alt' text
access_1.1.1.2	Access: [1.1.1.2]: suspicious 'alt' text (filename)
access_1.1.1.3	Access: [1.1.1.3]: suspicious 'alt' text (file size)
access_1.1.1.4	Access: [1.1.1.4]: suspicious 'alt' text (placeholder)
access_1.1.1.10	Access: [1.1.1.10]: suspicious 'alt' text (too long)
access_1.1.1.11	Access: [1.1.1.11]: <img> missing 'alt' text (bullet)
access_1.1.1.12	Access: [1.1.1.12]: <img> missing 'alt' text (horizontal rule)
access_1.1.2.1	Access: [1.1.2.1]: <img> missing 'longdesc' and d-link
access_1.1.2.2	Access: [1.1.2.2]: <img> missing d-link
access_1.1.2.3	Access: [1.1.2.3]: <img> missing 'longdesc'
access_1.1.2.5	Access: [1.1.2.5]: 'longdesc' not required
access_1.1.3.1	Access: [1.1.3.1]: <img> (button) missing 'alt' text
access_1.1.4.1	Access: [1.1.4.1]: <applet> missing alternate content
access_1.1.5.1	Access: [1.1.5.1]: <object> missing alternate content
access_1.1.6.1	Access: [1.1.6.1]: audio missing text transcript (wav)
access_1.1.6.2	Access: [1.1.6.2]: audio missing text transcript (au)
access_1.1.6.3	Access: [1.1.6.3]: audio missing text transcript (aiff)
access_1.1.6.4	Access: [1.1.6.4]: audio missing text transcript (snd)
access_1.1.6.5	Access: [1.1.6.5]: audio missing text transcript (ra)
access_1.1.6.6	Access: [1.1.6.6]: audio missing text transcript (rm)
access_1.1.8.1	Access: [1.1.8.1]: <frame> may require 'longdesc'
access_1.1.9.1	Access: [1.1.9.1]: <area> missing 'alt' text
access_1.1.10.1	Access: [1.1.10.1]: <script> missing <noscript> section
access_1.1.12.1	Access: [1.1.12.1]: ascii art requires description
access_1.2.1.1	Access: [1.2.1.1]: image map (server-side) requires text links
access_1.4.1.1	Access: [1.4.1.1]: multimedia requires synchronized text equivalents
access_1.5.1.1	Access: [1.5.1.1]: image map (client-side) missing text links
access_2.1.1.1	Access: [2.1.1.1]: ensure information not conveyed through color alone (image)
access_2.1.1.2	Access: [2.1.1.2]: ensure information not conveyed through color alone (applet)
access_2.1.1.3	Access: [2.1.1.3]: ensure information not conveyed through color alone (object)
access_2.1.1.4	Access: [2.1.1.4]: ensure information not conveyed through color alone (script)
access_2.1.1.5	Access: [2.1.1.5]: ensure information not conveyed through color alone (input)
access_2.2.1.1	Access: [2.2.1.1]: poor color contrast (text)
access_2.2.1.2	Access: [2.2.1.2]: poor color contrast (link)
access_2.2.1.3	Access: [2.2.1.3]: poor color contrast (active link)
access_2.2.1.4	Access: [2.2.1.4]: poor color contrast (visited link)
access_3.2.1.1	Access: [3.2.1.1]: <doctype> missing
access_3.3.1.1	Access: [3.3.1.1]: use style sheets to control presentation
access_3.5.1.1	Access: [3.5.1.1]: headers improperly nested
access_3.5.2.1	Access: [3.5.2.1]: potential header (bold)
access_3.5.2.2	Access: [3.5.2.2]: potential header (italics)
access_3.5.2.3	Access: [3.5.2.3]: potential header (underline)
access_3.6.1.1	Access: [3.6.1.1]: list usage invalid <ul>
access_3.6.1.2	Access: [3.6.1.2]: list usage invalid <ol>
access_3.6.1.4	Access: [3.6.1.4]: list usage invalid <li>
access_4.1.1.1	Access: [4.1.1.1]: indicate changes in language
access_4.3.1.1	Access: [4.3.1.1]: language not identified
access_4.3.1.2	Access: [4.3.1.2]: language attribute invalid
access_5.1.2.1	Access: [5.1.2.1]: data <table> missing row/column headers (all)
access_5.1.2.2	Access: [5.1.2.2]: data <table> missing row/column headers (1 col)
access_5.1.2.3	Access: [5.1.2.3]: data <table> missing row/column headers (1 row)
access_5.2.1.1	Access: [5.2.1.1]: data <table> may require markup (column headers)
access_5.2.1.2	Access: [5.2.1.2]: data <table> may require markup (row headers)
access_5.3.1.1	Access: [5.3.1.1]: verify layout tables linearize properly
access_5.4.1.1	Access: [5.4.1.1]: invalid markup used in layout <table>
access_5.5.1.1	Access: [5.5.1.1]: <table> missing summary
access_5.5.1.2	Access: [5.5.1.2]: <table> summary invalid (null)
access_5.5.1.3	Access: [5.5.1.3]: <table> summary invalid (spaces)
access_5.5.1.6	Access: [5.5.1.6]: <table> summary invalid (placeholder text)
access_5.5.2.1	Access: [5.5.2.1]: <table> missing <caption>
access_5.6.1.1	Access: [5.6.1.1]: <table> may require header abbreviations
access_5.6.1.2	Access: [5.6.1.2]: <table> header abbreviations invalid (null)
access_5.6.1.3	Access: [5.6.1.3]: <table> header abbreviations invalid (spaces)
access_6.1.1.1	Access: [6.1.1.1]: style sheets require testing (link)
access_6.1.1.2	Access: [6.1.1.2]: style sheets require testing (style element)
access_6.1.1.3	Access: [6.1.1.3]: style sheets require testing (style attribute)
access_6.2.1.1	Access: [6.2.1.1]: <frame> source invalid
access_6.2.2.1	Access: [6.2.2.1]: text equivalents require updating (applet)
access_6.2.2.2	Access: [6.2.2.2]: text equivalents require updating (script)
access_6.2.2.3	Access: [6.2.2.3]: text equivalents require updating (object)
access_6.3.1.1	Access: [6.3.1.1]: programmatic objects require testing (script)
access_6.3.1.2	Access: [6.3.1.2]: programmatic objects require testing (object)
access_6.3.1.3	Access: [6.3.1.3]: programmatic objects require testing (embed)
access_6.3.1.4	Access: [6.3.1.4]: programmatic objects require testing (applet)
access_6.5.1.1	Access: [6.5.1.1]: <frameset> missing <noframes> section
access_6.5.1.2	Access: [6.5.1.2]: <noframes> section invalid (no value)
access_6.5.1.3	Access: [6.5.1.3]: <noframes> section invalid (content)
access_6.5.1.4	Access: [6.5.1.4]: <noframes> section invalid (link)
access_7.1.1.1	Access: [7.1.1.1]: remove flicker (script)
access_7.1.1.2	Access: [7.1.1.2]: remove flicker (object)
access_7.1.1.3	Access: [7.1.1.3]: remove flicker (embed)
access_7.1.1.4	Access: [7.1.1.4]: remove flicker (applet)
access_7.1.1.5	Access: [7.1.1.5]: remove flicker (animated gif)
access_7.2.1.1	Access: [7.2.1.1]: remove blink/marquee
access_7.4.1.1	Access: [7.4.1.1]: remove auto-refresh
access_7.5.1.1	Access: [7.5.1.1]: remove auto-redirect
access_8.1.1.1	Access: [8.1.1.1]: ensure programmatic objects are accessible (script)
access_8.1.1.2	Access: [8.1.1.2]: ensure programmatic objects are accessible (object)
access_8.1.1.3	Access: [8.1.1.3]: ensure programmatic objects are accessible (applet)
access_8.1.1.4	Access: [8.1.1.4]: ensure programmatic objects are accessible (embed)
access_9.1.1.1	Access: [9.1.1.1]: image map (server-side) requires conversion
access_9.3.1.1	Access: [9.3.1.1]: <script> not keyboard accessible (onMouseDown)
access_9.3.1.2	Access: [9.3.1.2]: <script> not keyboard accessible (onMouseUp)
access_9.3.1.3	Access: [9.3.1.3]: <script> not keyboard accessible (onClick)
access_9.3.1.4	Access: [9.3.1.4]: <script> not keyboard accessible (onMouseOver)
access_9.3.1.5	Access: [9.3.1.5]: <script> not keyboard accessible (onMouseOut)
access_9.3.1.6	Access: [9.3.1.6]: <script> not keyboard accessible (onMouseMove)
access_10.1.1.1	Access: [10.1.1.1]: new windows require warning (_new)
access_10.1.1.2	Access: [10.1.1.2]: new windows require warning (_blank)
access_10.2.1.1	Access: [10.2.1.1]: <label> needs repositioning (<label> before <input>)
access_10.2.1.2	Access: [10.2.1.2]: <label> needs repositioning (<label> after <input>)
access_10.4.1.1	Access: [10.4.1.1]: form control requires default text
access_10.4.1.2	Access: [10.4.1.2]: form control default text invalid (null)
access_10.4.1.3	Access: [10.4.1.3]: form control default text invalid (spaces)
access_11.2.1.1	Access: [11.2.1.1]: replace deprecated html <applet>
access_11.2.1.2	Access: [11.2.1.2]: replace deprecated html <basefont>
access_11.2.1.3	Access: [11.2.1.3]: replace deprecated html <center>
access_11.2.1.4	Access: [11.2.1.4]: replace deprecated html <dir>
access_11.2.1.5	Access: [11.2.1.5]: replace deprecated html <font>
access_11.2.1.6	Access: [11.2.1.6]: replace deprecated html <isindex>
access_11.2.1.7	Access: [11.2.1.7]: replace deprecated html <menu>
access_11.2.1.8	Access: [11.2.1.8]: replace deprecated html <s>
access_11.2.1.9	Access: [11.2.1.9]: replace deprecated html <strike>
access_11.2.1.10	Access: [11.2.1.10]: replace deprecated html <u>
access_12.1.1.1	Access: [12.1.1.1]: <frame> missing title
access_12.1.1.2	Access: [12.1.1.2]: <frame> title invalid (null)
access_12.1.1.3	Access: [12.1.1.3]: <frame> title invalid (spaces)
access_12.4.1.1	Access: [12.4.1.1]: associate labels explicitly with form controls
access_12.4.1.2	Access: [12.4.1.2]: associate labels explicitly with form controls (for)
access_12.4.1.3	Access: [12.4.1.3]: associate labels explicitly with form controls (id)
access_13.1.1.1	Access: [13.1.1.1]: link text not meaningful
access_13.1.1.2	Access: [13.1.1.2]: link text missing
access_13.1.1.3	Access: [13.1.1.3]: link text too long
access_13.1.1.4	Access: [13.1.1.4]: link text not meaningful (click here)
access_13.1.1.5	Access: [13.1.1.5]: link text not meaningful (more)
access_13.1.1.6	Access: [13.1.1.6]: link text not meaningful (follow this)
access_13.2.1.1	Access: [13.2.1.1]: Metadata missing
access_13.2.1.2	Access: [13.2.1.2]: Metadata missing (link element)
access_13.2.1.3	Access: [13.2.1.3]: Metadata missing (redirect/auto-refresh)
access_13.10.1.1	Access: [13.10.1.1]: skip over ascii art