您需要在HTML中关闭元标记和链接标记吗？(Do you need to close meta and link tags in HTML?)

 标签必须始终被标签关闭符号> （如果我们忽略某些SGML规则，名义上应用于非XHTML HTML但从未在浏览器中实现）。 
 
 你的意思是要求这些元素是否需要由结束标签来关闭。 答案是非XHTML HTML（包括HTML序列化中的HTML5）， meta标签和link元素不需要或允许使用结尾标签。 然而，实际上，如果您使用浏览器，那么浏览器只会忽略它们的显式结束标记，以及货物崇拜/之前的。 而且，即使正式允许/在HTML序列化中，HTML5也使得这种允许性成为规则。 
 
 在XHTML中，XML规则适用，所以每个元素无一例外都必须同时具有起始标记和结束标签，但是如果元素内容为空，则可以为两个角色使用相同的标签，例如<meta name="foo" content="bar"/>作为<meta name="foo" content="bar"></meta>缩写。 如果在向符合规定的浏览器提供XML（XHTML）内容类型的文档时违反了这一点，那么您的文档根本不会显示; 将显示一条错误消息。 
 
 当使用具有HTML内容类型（ Content-Type: text/html ）的XHTML服务器时，由于XHTML文档几乎总是在网络上，所以浏览器实际上将应用非XHTML HTML规则。 
 
 总结： 
 
 
 
 通常，只使用<meta ...>与no / 
 
 
 如果您真正在XHTML解析实际应用的上下文中使用XHTML，则可以通过XML规则进行播放（并确保您了解它们） 
 
 
 如果你的老板告诉你写<meta ... /> ，那么 它没有用，但它不会造成伤害（除非您尝试验证例如agaist HTML 4.01 doctype）。 
 

A tag must always be closed by the tag close symbol > (if we ignore certain SGML rules that nominally apply in non-XHTML HTML but were never implemented in browsers).
 
What you mean to ask is whether the elements need to be closed by end tags. The answer is that non-XHTML HTML (including HTML5 in HTML serialization), no end tag is required or allowed for meta and link elements. In practice, however, browsers just ignore explicit end tags for them, as well as the cargo-cult / before >, if you use them. And HTML5 makes this permissiveness a rule by even formally allowing the / in HTML serialization, too.
 
In XHTML, XML rules apply, so every element, without exception, must have both a start tag and an end tag, but the same tag may be used for both roles if the element content is empty, e.g. <meta name="foo" content="bar"/> as short for <meta name="foo" content="bar"></meta>. If you violate this when serving a document with an XML (XHTML) content type to a conforming browser, then your document is not displayed at all; an error message is shown instead.
 
When using XHTML server with HTML content type (Content-Type: text/html), as XHTML documents almost always are on the web, then browsers will actually apply the non-XHTML HTML rules.
 
To summarize:
 
 
 
normally, use just <meta ...> with no /
 
 
if you are really using XHTML in a context where XHTML parsing is actually applied, play by XML rules (and make sure you know them)
 
 
if your boss tells you to write <meta ... />, do so; it’s not useful, but it causes no harm (except if you try to validate e.g. agaist HTML 4.01 doctype).