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/goldenPath/help/hubQuickStart.html src/hg/htdocs/goldenPath/help/hubQuickStart.html index 7a2e405832e..5c24def6633 100755 --- src/hg/htdocs/goldenPath/help/hubQuickStart.html +++ src/hg/htdocs/goldenPath/help/hubQuickStart.html @@ -43,32 +43,31 @@

If you are having problems, be sure all your files and the hg19 directory are publicly-accessible. For hubs to work, your server must also accept byte-ranges. You can check using the following command to verify "Accept-Ranges: bytes" displays:

curl -I http://yourURL/hub.txt

The three parts of a hub

Now that you have a working hub copied from above, you can edit the three main text documents to get an idea of how they work, and also point to your local files.

- +Example track hub directory structure showing hub.txt, genomes.txt, and trackDb.txt files

Example Hub Directory

Hubs begin with the short hub.txt, which describes your hub and informs the UCSC Browser where to find the underlying assemblies by defining the location of genomes.txt. The genomes.txt file outlines the hub's assemblies and defines the location of each assembly's trackDb.txt, which is basically the heart of your hub, defining the location of all the binary indexed track data for each assembly.

The hub.txt file can be as short as four lines, and the genomes.txt as short as two. The trackDb.txt file is typically much larger. At its most basic, it defines the tracks in the hub using stanzas about the type, location, and name of the binary files to display. However, it provides real power to tailor your presentation using additional trackDb settings.