chromium/third_party/blink/web_tests/external/wpt/css/CSS2/tables/background-table-README

See also:
   http://fantasai.tripod.com/www-style/2002/table-backgrounds/tests/
   https://dbaron.org/css/test/sec170501
   https://dbaron.org/css/test/sec170501a
   https://dbaron.org/css/test/sec170501b