Web Design in a Nutshell, 3rd Edition

Which Standard Is Right for You?

With so many co-existing Recommendations, it may be difficult to choose which one is best for your purposes. The following is a quick summary that will put all of these options into perspective.

XHTML 1.0 Transitional

Use this standard if your authoring style makes use of any of the deprecated elements (such as font) or attributes (such as bgcolor or align) and you have the discipline (or authoring tools) it takes to make sure the document is well-formed. This is the most popular choice for professional web developers because it is forward compatible, yet still allows some of the legacy techniques required to control presentation in current browsers.

XHTML 1.0 Strict

Use XHTML Strict if you are committed to using style sheets for all presentation and layout because all of those deprecated tags have been removed from this Recommendation. Documents must be well-formed as well, of course.

HTML 4.01

Use Transitional, Strict, or Frames if you aren’t concerned with site longevity, if you are not using updated authoring tools, or if you can’t bring yourself to close an li element.

XHTML 1.0 Frames or HTML 4.01 Frames

Use if you are creating a framed site. All deprecated attributes are still in there.

XHTML 1.1

This is available for use, but it is difficult to make it work effectively due to lack of browser support for the XML identifiers that a compliant XHTML 1.1 document requires. For this reason, it is not commonly used by developers as of this writing. ...