Why isn't doctype self-closing

2019-07-06 17:13发布

问题:

Provided an xhtml doctype like <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">, why is this tag itself allowed to be non self-closing / non closing at all?

Aka why isn't it: <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd" />

回答1:

It's not a tag (element). It's a declaration and that is the syntax for a declaration (doctype declaration specifically).

Other declarations (ELEMENT, ENTITY, ATTLIST, etc.) have a similar syntax. The > closes the declaration.



标签: xhtml doctype