HTML5 对各个标签的定义与规定：title

<span style="font-size: 12pt; color: rgb(61, 61, 61);" lang="EN-US"> <script language="javascript"></script></span>
<span style="font-size:12.0pt;color:#3D3D3D;mso-ansi-language: EN-US;mso-fareast-language:ZH-CN;mso-bidi-language:AR-SA" lang="EN-US">document.title = 'htmlv.cn';</span>
<span style="font-size:12.0pt;color:#3D3D3D;mso-ansi-language: EN-US;mso-fareast-language:ZH-CN;mso-bidi-language:&lt;/script&gt;&lt;/span&gt;&lt;/code&gt;写在head中，且只许出现一次。&lt;br&gt;&lt;/p&gt;&lt;span style=" font-size: font-family: mso-bidi-font-size: en-us .75pt mso-border-alt:dashed="" mso-bidi-theme-font:minor-bidi roman new="" minor-fareast mso-ascii-theme-font:minor-latin calibri lang="EN-US">内容类型为文本形式。<br><br>interface HTMLTitleElement : HTMLElement {<br>           attribute DOMString text;<br>};<br><br>title的标签中的内容用来表达文档的标题或名称。<br>在其他环境中也用title标签分别不同的html文档，例如书签中等。<br>调用或设置title的方法<br>interface HTMLTitleElement : HTMLElement {<br>           attribute DOMString text;<br>};<br><br>title的标签中的内容用来表达文档的标题或名称。<br>在其他环境中也用title标签分别不同的html文档，例如书签中等。<br>调用或设置title的方法<br><br>代码: 全选 运行<br>title . text [ = value ]<br><br>调用title的方法：document.title<br>所以上例中的代码实际应用中可以写成<br><br>……<br><br><script language="javascript"><br>document.title = 'htmlv.cn';<br></script><br><br>……<br><br></span><code><span style="FONT-SIZE: 12pt; COLOR: #3d3d3d; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA" lang="EN-US"> <script language="javascript"></script></span>
<span style="font-size:12.0pt;color:#3D3D3D;mso-ansi-language: EN-US;mso-fareast-language:ZH-CN;mso-bidi-language:AR-SA" lang="EN-US">document.title = 'htmlv.cn';</span>
<span style="font-size:12.0pt;color:#3D3D3D;mso-ansi-language: EN-US;mso-fareast-language:ZH-CN;mso-bidi-language:AR-SA" lang> </span><span style="FONT-SIZE: 12pt; COLOR: #3d3d3d; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA" lang="EN-US"></span>