Summary of html meta, introduction to the use of meta attributes in html tags

Quote: http://www.haorooms.com/post/html_meta_ds

Foreword

meta is an auxiliary tag in the head area of ​​html language. Maybe you think this code is dispensable. In fact, if you can make good use of meta tags, it will bring you unexpected effects. The functions of meta tags are: search engine optimization (SEO), defining the language used on the page, automatically refreshing and pointing to new pages, and realizing dynamics during web page conversion. Effect, control page buffering, web page rating and evaluation, control the window for web page display, etc.!

html meta summary

Composition of the meta tag: The meta tag has two attributes, which are the http-equiv attribute and the name attribute. Different attributes have different parameter values. These different parameter values ​​realize different web page functions.

1. name attribute

The name attribute is mainly used to describe web pages, and the corresponding attribute value is content. The content in content is mainly used by search engine robots to find information and classify information.

The syntax format of the name attribute of the

meta tag is:

<code><span class="tag"><meta<span class="pln"> <span class="atn">name<span class="pun">=<span class="atv">"参数"<span class="atn">content<span class="pun">=<span class="atv">"具体的参数值"<span class="tag">><span class="pln">。 </span></span></span></span></span></span></span></span></span></span></code>

The name attribute mainly has the following parameters:

A、Keywords　

Explanation: keywords are used to tell search engines what the keywords of your web page are.

Example:

<code><span class="tag"><meta<span class="pln"> <span class="atn">name<span class="pun">=<span class="atv">"keywords"<span class="atn">content<span class="pun">=<span class="atv">"meta总结,html meta,meta属性,meta跳转"<span class="tag">></span></span></span></span></span></span></span></span></span></code>

B、description(website content description)

Description: Description is used to tell search engines the main content of your website.

Example:

<code><span class="tag"><meta<span class="pln"> <span class="atn">name<span class="pun">=<span class="atv">"description"<span class="atn">content<span class="pun">=<span class="atv">"haorooms博客,html的meta总结，meta是html语言head区的一个辅助性标签。"<span class="tag">></span></span></span></span></span></span></span></span></span></code>

C, robots (robot guide)

Description: Robots are used to tell search robots which pages need to be indexed and which pages do not need to be indexed.

The parameters of content include all, none, index, noindex, follow, and nofollow. The default is all.

Example:

<code><span class="tag"><meta<span class="pln"> <span class="atn">name<span class="pun">=<span class="atv">"robots"<span class="atn">content<span class="pun">=<span class="atv">"none"<span class="tag">></span></span></span></span></span></span></span></span></span></code>

The specific parameters are as follows:

The information parameter is all: the file will be retrieved and the links on the page can be queried;

The information parameter is none: the file will not be retrieved, and the links on the page cannot be queried;

The information parameter is index: the file will be retrieved;

The information parameter is follow: links on the page can be queried;

The information parameter is noindex: the file will not be retrieved, but the links on the page can be queried;

The information parameter is nofollow: the file will be retrieved, but the links on the page cannot be queried;

D、author(author)

Instructions: Mark the author of the webpage

Example:

<code><span class="tag"><meta<span class="pln"> <span class="atn">name<span class="pun">=<span class="atv">"author"<span class="atn">content<span class="pun">=<span class="atv">"root,root@xxxx.com"<span class="tag">></span></span></span></span></span></span></span></span></span></code>

E、generator

<code><span class="tag"><meta<span class="pln"> <span class="atn">name<span class="pun">=<span class="atv">"generator"<span class="atn">content<span class="pun">=<span class="atv">"信息参数"<span class="tag">/></span></span></span></span></span></span></span></span></span></code>

The generator information parameter of the meta tag represents the software used to create the website.

F、COPYRIGHT

<code><span class="tag"><META<span class="pln"> <span class="atn">NAME<span class="pun">=<span class="atv">"COPYRIGHT"<span class="atn">CONTENT<span class="pun">=<span class="atv">"信息参数"<span class="tag">></span></span></span></span></span></span></span></span></span></code>

The COPYRIGHT information parameter of the meta tag represents website copyright information.

G、revisit-after

<code><span class="tag"><META<span class="pln"> <span class="atn">name<span class="pun">=<span class="atv">"revisit-after"<span class="atn">CONTENT<span class="pun">=<span class="atv">"7days"<span class="tag">></span></span></span></span></span></span></span></span></span></code>

revisit-after represents website revisit, 7days represents 7 days, and so on.

2. http-equiv attribute

http-equiv, as the name suggests, is equivalent to the file header function of http. It can return some useful information to the browser to help display web page content correctly and accurately. The corresponding attribute value is content, and the content in content is actually It is the variable value of each parameter.

The http-equiv attribute syntax format of

meta tag is:

<code><span class="tag"><meta<span class="pln"> <span class="atn">http-equiv<span class="pun">=<span class="atv">"参数"<span class="atn">content<span class="pun">=<span class="atv">"参数变量值"<span class="tag">><span class="pln">； </span></span></span></span></span></span></span></span></span></span></code>

The http-equiv attribute mainly has the following parameters:

A、Expires

Description: Can be used to set the expiration time of the web page. Once a web page expires, it must be retransmitted to the server.

Usage:

<code><span class="tag"><meta<span class="pln"> <span class="atn">http-equiv<span class="pun">=<span class="atv">"expires"<span class="atn">content<span class="pun">=<span class="atv">"Fri,12Jan200118:18:18GMT"<span class="tag">></span></span></span></span></span></span></span></span></span></code>

Note: GMT time format must be used.

B, Pragma (cache mode)

Description: Disable the browser from accessing page content from the local computer's cache.

Usage:

<code><span class="tag"><meta<span class="pln"> <span class="atn">http-equiv<span class="pun">=<span class="atv">"Pragma"<span class="atn">content<span class="pun">=<span class="atv">"no-cache"<span class="tag">></span></span></span></span></span></span></span></span></span></code>

Note: With this setting, visitors will not be able to browse offline.

C、Refresh

Description: Automatically refresh and point to new page.

Usage:

<code><span class="tag"><meta<span class="pln"> <span class="atn">http-equiv<span class="pun">=<span class="atv">"Refresh"<span class="atn">content<span class="pun">=<span class="atv">"2;URL=http://www.haorooms.com"<span class="tag">><span class="pln"> //(注意后面的引号，分别在秒数的前面和网址的后面) </span></span></span></span></span></span></span></span></span></span></code>

Note: The 2 refers to automatically refreshing to the URL after staying for 2 seconds.

D、Set-Cookie(cookie setting)

Note: If the web page expires, the saved cookies will be deleted.

Usage:

<code><span class="tag"><meta<span class="pln"> <span class="atn">http-equiv<span class="pun">=<span class="atv">"Set-Cookie"<span class="atn">content<span class="pun">=<span class="atv">"cookie value=xxx;expires=Friday,12-Jan-200118:18:18GMT；path=/"<span class="tag">></span></span></span></span></span></span></span></span></span></code>

Note: GMT time format must be used.

E, Window-target (display window setting)

Description: Force the page to be displayed as an independent page in the current window.

Usage:

<code><span class="tag"><meta<span class="pln"> <span class="atn">http-equiv<span class="pun">=<span class="atv">"Window-target"<span class="atn">content<span class="pun">=<span class="atv">"_top"<span class="tag">></span></span></span></span></span></span></span></span></span></code>

Note: Used to prevent others from calling your own page in the frame.

F, content-Type (display character set setting)

Description: Set the character set used by the page.

Usage:

<code><span class="tag"><meta<span class="pln"> <span class="atn">http-equiv<span class="pun">=<span class="atv">"content-Type"<span class="atn">content<span class="pun">=<span class="atv">"text/html;charset=gb2312"<span class="tag">></span></span></span></span></span></span></span></span></span></code>

The details are as follows:

When the charset information parameter of the meta tag is such as GB2312, it means that the encoding used by the website is Simplified Chinese;

When the charset information parameter of the meta tag is such as BIG5, it means that the encoding used by the website is Traditional Chinese;

When the charset information parameter of the meta tag is such as iso-2022-jp, it means that the encoding used by the website is Japanese;

When the charset information parameter of the meta tag is such as ks_c_5601, it means that the encoding used by the website is Korean;

When the charset information parameter of the meta tag is such as ISO-8859-1, it means that the encoding used by the website is English;

When the charset information parameter of the meta tag is such as UTF-8, it represents the world's universal language encoding;

G、content-Language（显示语言的设定）

用法：

<code><span class="tag"><meta<span class="pln"> <span class="atn">http-equiv<span class="pun">=<span class="atv">"Content-Language"<span class="atn">content<span class="pun">=<span class="atv">"zh-cn"<span class="tag">/></span></span></span></span></span></span></span></span></span></code>

H、Cache-Control指定请求和响应遵循的缓存机制。

Cache-Control指定请求和响应遵循的缓存机制。在请求消息或响应消息中设置Cache-Control并不会修改另一个消息处理过程中的缓存处理过程。请求时的缓存指令包括no-cache、no-store、max-age、max-stale、min-fresh、on

ly-if-cached，响应消息中的指令包括public、private、no-cache、no-store、no-transform、must-revalidate、proxy-revalidate、max-age。各个消息中的指令含义如下

Public指示响应可被任何缓存区缓存

Private指示对于单个用户的整个或部分响应消息，不能被共享缓存处理。这允许服务器仅仅描述当用户的部分响应消息，此响应消息对于其他用户的请求无效

no-cache指示请求或响应消息不能缓存

no-store用于防止重要的信息被无意的发布。在请求消息中发送将使得请求和响应消息都不使用缓存。

max-age指示客户机可以接收生存期不大于指定时间（以秒为单位）的响应

min-fresh指示客户机可以接收响应时间小于当前时间加上指定时间的响应

max-stale指示客户机可以接收超出超时期间的响应消息。如果指定max-stale消息的值，那么客户机可以接收超出超时期指定值之内的响应消息。

J、http-equiv="imagetoolbar"

<code><span class="tag"><meta<span class="pln"> <span class="atn">http-equiv<span class="pun">=<span class="atv">"imagetoolbar"<span class="atn">content<span class="pun">=<span class="atv">"false"<span class="tag">/></span></span></span></span></span></span></span></span></span></code>

指定是否显示图片工具栏，当为false代表不显示，当为true代表显示。

K、Content-Script-Type

<code><span class="tag"><Meta<span class="pln"> <span class="atn">http-equiv<span class="pun">=<span class="atv">"Content-Script-Type"<span class="atn">Content<span class="pun">=<span class="atv">"text/javascript"<span class="tag">></span></span></span></span></span></span></span></span></span></code>

W3C网页规范，指明页面中脚本的类型。

L 页面跳转，只用于IE