On the theme settings page users can add a new site logo, but cannot change the alternative text, alt attribute, for the logo image. Currently the alt attribute for all Core themes are hard coded into page.tpl.php as "Home", with the exception of Garland, which uses $site_name_and_slogan.
Provide a 'logo_alt_text' setting on the theme settings form, and modify Core themes to provide a default for this setting in their .info file.
Modify patch in #14
1.Make sure that Logo alternative text #textfield is available even when using default theme logo.
2. Remove default for 'logo_alt_text' from theme_get_settings()
3. Update Core theme .info files to provide
setting[logo_alt_text] = default alt text
User interface changes
A new Logo alternative text textfield will be added to the logo section of the theme settings form.
1. The alt attribute for theme logos should no longer be hard coded into page.tpl.php, but should be printed from $logo_alt_text.
2. Themes should define the default alt text for their logo in the theme .info file using:
settings[logo_alt_text] = Alternative text
Original report by Everett Zufelt
When administrators add a custom logo to any of the core themes they are not able to add a custom alt attribute for the image. By default the alt attribute assigned to the logo image (whether the image is the default theme logo or a custom logo) is the site name.
In order to meet the WCAG 2.0 accessibility guideline images that convey information must be marked up with an appropriate alt attribute. Not all images will require a custom alt attribute, but some will, and the ability to provide this currently does not exist for core themes.