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2008-09-25 16:06:51

The declaration is the very first thing in your document, before the tag. This tag tells the browser which HTML or XHTML specification the document uses.

Note: The tag does not have an end tag!

HTML
HTML 4.01 specifies three document types: Strict, Transitional, and Frameset.


HTML Strict DTD

Use this when you want clean markup, free of presentational clutter. Use this together with Cascading Style Sheets (CSS):

Example Source Code []


HTML Transitional DTD

The Transitional DTD includes presentation attributes and elements that W3C expects to move to a style sheet. Use this when you need to use HTML's presentational features because your readers don't have browsers that support Cascading Style Sheets (CSS):

Example Source Code []


Frameset DTD
The Frameset DTD should be used for documents with frames. The Frameset DTD is equal to the Transitional DTD except for the frameset element replaces the body element:

Example Source Code []


XHTML
XHTML 1.0 specifies three XML document types: Strict, Transitional, and Frameset.


XHTML Strict DTD

Use this DTD when you want clean markup, free of presentational clutter. Use this together with Cascading Style Sheets (CSS):

Example Source Code []

  
XHTML Transitional DTD

Use this DTD when you need to use XHTML's presentational features because your readers don't have browsers that support Cascading Style Sheets (CSS):

Example Source Code []


XHTML Frameset DTD

Use this DTD when you want to use frames!

Example Source Code []


To check that you have written a valid XHTML document with a correct DTD,  you can link your XHTML page to an XHTML validator.


      
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