5709a7858d5c197721be66d5218a79124abadb70
lrnassar
  Tue Mar 17 08:46:31 2026 -0700
Adding alt text to images across static documentation pages, CGI headers, markdown docs, and Pandoc templates. Content images receive AI-generated descriptive alt text; decorative images (icons, spacers, toggles) receive alt="" per WCAG best practice. Also adds Image Descriptions section to the accessibility page, and fixes Pandoc Lua writers to output alt attributes. 67 files, covering help docs, news archive, ENCODE pages, portal pages, and session examples. refs #37254

diff --git src/hg/htdocs/ENCODE/index.html src/hg/htdocs/ENCODE/index.html
index 635bce4d4c4..388749ee30d 100755
--- src/hg/htdocs/ENCODE/index.html
+++ src/hg/htdocs/ENCODE/index.html
@@ -134,57 +134,57 @@
 
                 </div><!--end content-->
             </div><!--end wrapper-->
             </td>
             </tr>
 
 
             <!-- screenshot launchers 2x2 matrix -->
                 <tr>
                     <td>
                     <div style="margin-left:10px;" class="wrapper">
                     <!--<div style="height:100%; margin-top:0; margin-left:10px; margin-right:10px" class="wrapper">
                     -->
                         <div class="bar"><h4 class="title">Explore ENCODE data (2003 - 2012) at UCSC</h4></div>
                         <div class="content">
-                            <a  href="dataMatrix/encodeDataMatrixHuman.html"><img class="screenshot" src="../images/encode/dataMatrix.png"></a>
+                            <a  href="dataMatrix/encodeDataMatrixHuman.html"><img class="screenshot" alt="ENCODE experiment matrix showing assay types across cell lines organized by tier" src="../images/encode/dataMatrix.png"></a>
                         </div>
                     </div> <!-- end wrapper -->
                     </td>
                     <td>
                     <div style="margin-left:10px;" class="wrapper">
                     <!--
                     <div style="height: 100%; margin-top:0;" class="wrapper">
                     -->
                         <div class="bar"><h4 class="title">View ENCODE data (2003 - 2012) in the UCSC Genome Browser</h4></div>
-                            <a href="../cgi-bin/hgTracks?hgS_doLoadUrl=submit&hgS_loadUrlName=http://genome.ucsc.edu/goldenPath/help/examples/sessions/encodeDemonstration"><img class="screenshot"  src="../images/encode/browser.png"></a>
+                            <a href="../cgi-bin/hgTracks?hgS_doLoadUrl=submit&hgS_loadUrlName=http://genome.ucsc.edu/goldenPath/help/examples/sessions/encodeDemonstration"><img class="screenshot"  alt="Genome Browser showing ENCODE histone marks, DNase clusters, and transcription factor ChIP-seq tracks" src="../images/encode/browser.png"></a>
                     </div>
                     </td>
                 </tr>
 
                 <tr>
                     <td>
                     <div style="margin-left:10px;" class="wrapper">
                     <!--
                     <div style="height: 100%; margin-top:10px; margin-left:10px; margin-right:10px" class="wrapper">
                     -->
                         <div class="bar"><h4 class="title">Search for data (current) at the ENCODE Portal</h4></div>
-                            <a href="https://www.encodedcc.org/search/?type=experiment"><img class="screenshot" style="display: block; margin: auto;" src="../images/encode/stanfordSearch.png"></a>
+                            <a href="https://www.encodedcc.org/search/?type=experiment"><img class="screenshot" style="display: block; margin: auto;" alt="ENCODE Portal search results page listing experiments with faceted filtering" src="../images/encode/stanfordSearch.png"></a>
                     </div>
                     </td>
                     <td>
                     <div style="margin-left:10px;" class="wrapper">
                     <!--
                     <div style="height: 100%; margin-top:10px" class="wrapper">
                     -->
                         <div class="bar"><h4 class="title">Search for ENCODE tracks (2003 - 2012) in the UCSC Browser</h4></div>
-                            <a href="../cgi-bin/hgTracks?hgt_=1408334670&db=hg19&tsCurTab=advancedTab&hgt_tsDelRow=&hgt_tsAddRow=&hgt_tsPage=&tsSimple=&tsName=&tsDescr=&tsGroup=Any&tsType=Any&hgt_mdbVar1=cell&hgt_mdbVal1=HeLa-S3&hgt_mdbVar2=dataType&hgt_mdbVal2=RnaSeq&hgt_tSearch=search"><img class="screenshot" src="../images/encode/search.png"></a>
+                            <a href="../cgi-bin/hgTracks?hgt_=1408334670&db=hg19&tsCurTab=advancedTab&hgt_tsDelRow=&hgt_tsAddRow=&hgt_tsPage=&tsSimple=&tsName=&tsDescr=&tsGroup=Any&tsType=Any&hgt_mdbVar1=cell&hgt_mdbVal1=HeLa-S3&hgt_mdbVar2=dataType&hgt_mdbVal2=RnaSeq&hgt_tSearch=search"><img class="screenshot" alt="UCSC track search interface with ENCODE filters showing matching tracks" src="../images/encode/search.png"></a>
                     </div>
                     </td>
                 </tr>
             <!-- screenshot launchers -->
             </table>
         </td>
     </tr>
     </table>
 </body>
 </html>