The HTML 4.01 standard is formally defined
as three SGML Document Type Definitions (DTDs): the
Strict DTD, the Transitional DTD, and the
Frameset DTD. The Strict DTD defines only those elements that are not
deprecated in the 4.0 standard.
Ideally, everyone would create HTML documents that conform to the
Strict DTD. The Transitional DTD includes all those deprecated
elements and more accurately reflects the HTML in use today, with
many older elements still in common use. The Frameset DTD is
identical to the Transitional DTD, with the exception that the
<body> is replaced by the
Since the Transitional DTD provides the broadest coverage of all HTML elements currently in use, it is the DTD upon which this book is based and the one we reproduce here. Note that we have reprinted this DTD verbatim and have not attempted to add extensions to it. Where our description and the DTD deviate, assume the DTD is correct.
<!-- This is the HTML 4.01 Transitional DTD, which includes presentation attributes and elements that W3C expects to phase out as support for style sheets matures. Authors should use the Strict DTD when possible, but may use the Transitional DTD when support for presentation attributes and elements is required. HTML 4 includes mechanisms for style sheets, scripting, embedding objects, improved support for right to left and mixed direction text, and enhancements to forms for improved accessibility for people with disabilities. ...