Note: the DOCTYPE declaration is not a part of the XHTML document itself. It is not an XHTML element and it should not have a closing tag.

注意：DOCTYPE声明并不是XHTML文档自身的一部分。它也不是XHTML元素，它不该有关闭标签。

youdao

The declaration is not a part of the XML document itself. It is not an XML element, and it should not have a closing tag.

声明并不是XML文档本身的一部分，它也不是一个XML元素，所以它并不需要包含结束标签。

youdao

Note: You might have noticed from the previous example that the XML declaration did not have a closing tag.

注意：也许你在前面的案例中已经注意到，XML声明并没有包含结束标签。

youdao