Several accessibility issues:
- The list of users with images, eg 'Users tagged with "Moodle": 42' should be marked up as an unordered list <ul> - use "inline-list" class,
- As the user images are the only contents of a link they should NOT have empty ALT text - basic stuff!
I have a patch, tested on Win/Firefox 22.214.171.124 and IE 6, affecting 2 files:
- tag/lib.php, print_user_list (clue in the name) and print_user_box functions.
- theme/standard/styles_layout.css - a long overdue fix for "inline-list" class!
(Also see bug