XHTML Doc Types

There are 3 Doctypes usable by an XHTML document. Strict, Transitional, and Frameset. The doctype is used when validating an XHTML document's content against a DTD and reporting markup errors. (The DOCTYPE lines below are broken in parts only to prevent the examples from being too wide for non-horizontal scrolling - you can keep it all on one line).

XHTML 1.0 Strict

Use this when you want really clean markup, free of presentational clutter. Use this together with Cascading Style Sheets.

"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">


XHTML 1.0 Transitional

Use this when you need to take advantage of HTML's presentational features because many of your readers don't have the latest browsers that understand Cascading Style Sheets.

"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">


XHTML 1.0 Frameset

Use this when you want to use HTML Frames to partition the browser window into two or more frames.

"http://www.w3.org/TR/xhtml1/DTD/xhtml1-frameset.dtd">