HTML and CSS Reference
HTML or XHTML Version
Classic HTML dialect supported by browsers such as Mosaic. This
form of HTML supports core HTML elements and features such as
tables and forms, but does not consider any of the browser innovations
of advanced features such as style sheets, scripting, or frames.
The proposed replacement for HTML 2.0 that was never widely
adopted, most likely due to the heavy use of browser-specific markup.
An HTML finalized by the W3C in early 1997 that standardized most of
the HTML features introduced in browsers such as Netscape 3. This
version of HTML supports many presentation-focused elements such
as font , as well as early support for some scripting features.
HTML 4.0 Transitional
The 4.0 transitional form finalized by the W3C in December of 1997
preserves most of the presentational elements of HTML 3.2. It
provides a basis of transition to Cascading Style Sheets (CSS) as
well as a base set of elements and attributes for multiple-language
support, accessibility, and scripting.
HTML 4.0 Strict
The strict version of HTML 4.0 removes most of the presentation
elements from the HTML specification, such as font , in favor of using
CSS for page formatting.
The frameset specification provides a rigorous syntax for framed
documents that was lacking in previous versions of HTML.
HTML 4.01 Transitional/
A minor update to the 4.0 standard that corrects some of the errors in
the original specification.
Addressing the lack of acceptance of the XML reformulation of HTML
by the mass of Web page authors, the emerging HTML5 standard
originally started by the WHATWG 3 group and later rolled into a W3C
effort aimed to rekindle the acceptance of traditional HTML and
extend it to address Web application development, multimedia, and
the ambiguities found in browser parsers. Since 2005, features now
part of this HTML specification have begun to appear in Web browsers,
muddying the future of XHTML in Web browsers.
XHTML 1.0 Transitional
A reformulation of HTML as an XML application. The transitional
form preserves many of the basic presentation features of HTML 4.0
transitional but applies the strict syntax rules of XML to HTML.
XHTML 1.0 Strict
A reformulation of HTML 4.0 Strict using XML. This language is rule
enforcing and leaves all presentation duties to technologies like CSS.
A restructuring of XHTML 1.0 that modularizes the language for easy
extension and reduction. It is not commonly used at the time of this
writing and offers minor gains over strict XHTML 1.0.
3 Web Hypertext Application Technology Working Group (www.whatwg.org).
T ABLE 1-1 Description of Common HTML Versions