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Meet XHTML 2.0
On August 5, the W3C released the first of what will probably be several work drafts of specifications for XHTML 2.0, the ultimate successor earlier versions of XHTML and HTML alike. Because this technology might -- and I stress that word "might" because XHTML hasn't exactly taken over the world for plain-vanilla Web pages just yet -- eventually be important, I want to cover some highlights of what's new about this draft version, and speculate on what it might mean to "Joe Web developer" or "Jane content developer" in years to come.
To begin with, XHTML 2.0 incorporates all kinds of elements and capabilities associated with work underway at the W3C and elsewhere on the so-called "semantic Web." This initiative seeks to make it as easy for computers to exchange information about what's on Web sites and how to find same as it is for humans to communicate about such things among themselves. While this initiative is pretty interesting and has produced some fascinating (but neither mainstream nor completely intuitive) results -- see the W3 coverage and Scientific American for more information -- the initiative and its use are still in their infancy, so I move on to other, more mundane but probably useful innovations in XHTML 2.0.
In a nutshell, here are the many changes and innovations that XHTML 2.0 has to offer:
- Citations and quotes: New markup replaces the q element with a quote element with better labeling and source attribution controls; likewise, citation information becomes an attribute to the quote element, rather than a separate element whose content identifies a source. This helps tie quotations to sources more closely, and should prevent the kind of abuse that occurs so much for q and cite elements, often used purely for presentation controls in HTML and XHTML today.
- Line breaks: because interpretation of what the line break element (br) means when parsing SGML or XML has been tricky -- designers use it to force display behavior, purists deplore it altogether -- XHTML 2.0 eliminates the br element. No more controversy, no more br, either.
- Navigation lists: lots of scripting and widgetry is devoted to creating customized and incompatible navigation tools for Web pages. XHTML 2.0 cuts this Gordian knot by introducing the nestable nl (navigation list) element which makes it easy to define and control navigation elements in a straightforward, standard way.
- Object rules: In XHTML 2.0 applet and img elements disappear, to be replaced by a single, standard object element. This regularizes syntax and access to objects (graphics, code, scripts, multimedia, and so forth) outside XHTML or XML control and should help clean up and simplify access to external objects.
- Unordered sections and headings: Rather than sticking with numbered h1 through h6 heading levels, XHTML 2.0 introduces the generic h element which can be arbitrarily nested and used as needed. It removes the temptation to violate heading levels for appearance sake, and also makes it easier for content developers to control use and structure of document headings. For those in the know, it works more like DOCBOOK now.
- Widely extended notion of linking: In XHTML 2.0, the href attribute joins the "common attribute collection" or CAC. In plain English this means two things: all XHTML elements will therefore contain that attribute, and all XHTML elements will therefore be linkable. This will help to simplify writing XHTML and will make it easier than ever before for designers to use linking structures in a more intuitive way.
By and large, these changes appear very much for the better in terms of simplifying document structure, further divorcing display from structure controls, and making various syntax elements simpler to use and understand. Though many drafts lie ahead, this work seems headed in the right direction!
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About the Author
Ed Tittel is a principal at LANWrights, Inc., a network-oriented writing, training, and consulting firm based in Austin, Texas. He is the creator of the Exam Cram series and has worked on over 30 certification-related books on Microsoft, Novell, and Sun related topics. Ed teaches in the Certified Webmaster Program at Austin Community College and consults. He a member of the NetWorld + Interop faculty, where he specializes in Windows 2000 related courses and presentations.
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