An XHTML document is validated against a Document Type Definition.

依靠文档类型定义来校验XHTML文档。

Validate XHTML With A DTD

通过DTD校验XHTML

An XHTML document is validated against a Document Type Definition (DTD). Before an XHTML file can be properly validated, a correct DTD must be added as the first line of the file.

要正确校验XHTML文件就必须在首行加入恰当的DTD。

The Strict DTD includes elements and attributes that have not been deprecated or do not appear in framesets:

严密型DTD包括非框架或非不赞成的元素和属性（只包含完全符合标准规范的元素和属性）：

!DOCTYPE html PUBLIC

"-//W3C//DTD XHTML 1.0 Strict//EN"

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

The Transitional DTD includes everything in the strict DTD plus deprecated elements and attributes:

过渡型可包含所有严密型DTD所不赞成使用的元素和属性：

!DOCTYPE html PUBLIC

"-//W3C//DTD XHTML 1.0 Transitional//EN"

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

The Frameset DTD includes everything in the transitional DTD plus frames as well:

框架型可包含过渡型所有的元素和属性同时能够使用框架：

!DOCTYPE html PUBLIC

"-//W3C//DTD XHTML 1.0 Frameset//EN"

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

This is a simple XHTML document:

简单的XHTML文档实例：

PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"

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

simple document

a simple paragraph

Test Your XHTML With The W3C Validator

用W3C校验器来测试你的XHTML

在下面添加你页面的地址：