The following table shows the elements and attributes defined in each significant version of HTML. Items marked with an asterisk, '*', are not supported by the latest version of at least one of the most popular Web browsers, so should be used with caution.
There are a very large number of attributes first defined in HTML 4.0. Many of them are defined using entities. To keep this table to a reasonable size, these groups are described here, and given the names 'Core', 'Events' and 'Lang' for reference under appropriate elements.
Core attributes: Id, Title, Class, Style.
Language attributes: Lang (and xml:lang in XHTML), Dir.
Event attributes: Onclick, Ondblclick, Onmousedown, Onmouseup, Onmouseover, Onmouseout, ...