This style sheet describes the typical formatting of all HTML 4.0
([HTML40]) elements based on extensive research into current UA
practice. Developers are encouraged to use it as a default style sheet
in their implementations.
The full presentation of some HTML elements cannot be expressed in
CSS 2.1, including replaced
elements ("img", "object"), scripting elements ("script", "applet"), form
control elements, and frame elements.
For other elements, the legacy presentation can be described in CSS
but the solution removes the element. For example, the FONT element
can be replaced by attaching CSS declarations to other elements (e.g.,
DIV). Likewise, legacy presentation of presentational attributes
(e.g., the "border" attribute on TABLE) can be described in CSS, but
the markup in the source document must be changed.