On December 17, 1997 HTML 4.0 was accepted as the working standard for hypertext documents. This really doesn't make a lot of difference for people who already have an understanding of Standard Generalized Markup Language, or SGML; the parent-language of HTML. But for those who do not understand SGML, particularly people who have never authored a HTML page before, the difference between HTML 3.2 and HTML 4.0 is pretty extreme and portends only more extreme differences in future versions of HTML. Therefore this tutorial will give examples of both HTML 3.2 and HTML 4.0 code when the differences are obvious.

For the most part, authoring a document using HTML 4.0 isn't that different from authoring a document using HTML 3.2 apart from the fact that HTML 4.0 allows significantly less direct control over the appearance of the document (which is more in line with the SGML philosophy). This means that HTML 4.0 documents will not have, most significantly, the <FONT...> or <CENTER> elements. The function of the elements which control the appearance of a document is, for the most part, now given to Level 2 Cascading Style Sheets. Cascading Style Sheets (CSS2) will be somewhat more difficult to learn for those who have no understanding of typefaces, font sizes, line spacing and other details which specify how a particular piece of text should appear, however even these details are easy enough to learn when you can see examples, which is what I hope to accomplish with this tutorial.

The following styles will be used throughout this tutorial in order to clarify examples:

• Hyperlinks will appear in teal underlined grotesque type (links should change to black once you've visited them).
• New terms and concepts, or concepts that need to be emphasized will be presented in bold Roman type.
• URIs used in examples will appear in dark blue underlined monospaced type.
• Tags and attributes used in examples will appear in dark purple monospaced type.
• Text appearing in examples will appear in grey bold grotesque type.
• Lists of URIs or other resources will appear in a blue bold grotesque type headline.

If you are unable to see these styles, or if all the text you see appears to be in the same style of type with no variations, then you are using a browser which does not support CSS2. As of this writing, Netscape Navigator 4.0x, Microsoft Internet Explorer 3.x and Microsoft Internet Explorer 4.x are the only browsers I know of that support CSS2 (as I am writing this I am discovering that, while Cascading Style Sheets were originally a Microsoft "innovation" - meaning that CSS was first implimented on the MS browser - they are actually better supported at this point by just about any other browser, a fact which I consider somewhat amusing). I suspect that there are other browsers, particularly those designed for the Unix/Linux platform that will be comparable. Please contact me with any further information you may have concerning browsers which support CSS2. As I am not in the business of selling software, I really don't care whose browser you use, however if you choose not to use a browser which supports CSS2, this tutorial will be considerably less readable for you and you might want to consider upgrading.

This tutorial is "the next generation," or third edition of materials I put together for a class I taught in 1996. Since then I have been teaching random classes in HTML usage and the differences between HTML 3.2 and HTML 4.0, and in the Cascading Style Sheet specification. The hypertext markup language is constantly being refined and upgraded. The standard is somewhat of a moving target and writing "valid" HTML is a difficult and painstaking process. Software manufacturers are constantly adding their own new, proprietary extensions, changing implimentation of the current standard, schmoozing around with software support and, in general, making things difficult for those who want to know how to do it correctly. If you find any errors or know of anything which should be added to this tutorial, please feel free to contact me with suggestions.