(1.1) An image element should have some descriptive text: an alt or longdesc attribute. (1.1) An input element should have some descriptive text: an alt or longdesc attribute. (1.1) An applet element should have some descriptive text: an alt or longdesc attribute. (1.1) A map element should have some descriptive text: an alt attribute or a link. (1.1) An object element should contain some descriptive text. (1.1) A frame element should have some descriptive text: a longdesc attribute. (2.2) The background color and the foreground color are the same (3.3) Concerning element : B and I are not recommended. Use strong and em, or stylesheets. (3.3) A list should not be used for formatting effects (4.3) The primary language of a document should be identified. (5.1) A table should have a caption (5.5) A table should have a summary attribute (5.2) Table data should identify its scope, headers, axis in attributes. (5.6) A table header should have an abbr attribute to give abbreviation (6.4) If you specify an "onmouseup" attribute on a element, you should also specify an "onkeyup" attribute (6.4) If you specify an "onmousedown" attribute on a element, you should also specify an "onkeydown" attribute (6.4) If you specify an "onclick" event on a element, you should also specify an "onkeypress" (6.5) The marquee element is not good HTML (6.5) The blink element is not good HTML (6.2) A frame should not be a direct image (6.5) If you specify a frame, also specify a noframes element. (7.1) The user should control the refreshing of the page (?) A fieldset should have a legend (12.1) A frameset should have a title