About HTTP request Headers: HTTP-EQUIV

Source: Internet
Author: User

Statement: 2016.8.19 I copied a Sina blog, designed to record what the ghost of http-equiv, related to the interests of the issue please contact ME. (generally not involved) What does HTTP-EQUIV mean to be published in June 25, 2012By Build a station tutorial

1. Definition Language


〈meta http-equiv=〃content-type〃content=〃text/html; charset=gb2312〃〉

This is the most common use of meta, in the production of Web pages, under the pure HTML code will see it, it is to define the language of your Web page, when visitors browse your page, the browser will automatically recognize and set the language in the page, if your page is set to GB code, and visitors do not install GB code, The Web page will only present the browser default language set by the Visitor. similarly, if the webpage is english, then Charset=en.

2. description page


〈meta name=〃keywords〃content=〃china,enterprise,business,net〃〉

Meta is also commonly used to describe web pages for use by certain search platform Robots. As you know, the search platform is divided into two categories, one for full manual login, such as yahoo, and the other for robot search, the search platform for robot search will contain more Content. The robot searches for the descriptive keywords set in the META tag of the Web page and adds them to the search database to index your Pages. And this tag is rarely noticed by anyone. In the format, the content lists the keywords you set, which can be set by itself, separated by Commas. Here's a tip that you can repeat a word to improve your Site's ranking, such as:

〈meta name=〃keywords〃content=〃china,china,china,china〉

3. Automatically refresh the page


〈meta http-equiv=〃refresh〃content=〃8; Url=http://c98.yeah.net〃〉

When you browse a webpage, you will find that some pages automatically go to another page after a few seconds, which is the refresh of meta, in content, 8 is the number of seconds to set, and the URL is the Web address automatically connected after 8 SECONDS.

4. Website Grading Evaluation


〈meta Http-equiv=〃pics-label〃

content=′ (pics-1.1〃http://www.rsac.org/ratingsv01.html

L Gen True Comment〃rsaci North America Server〃



R (n 0 S 0 v 0 L 0)) ′〉

There is a content setting in Internet Explorer 4.0 browser Internet Options that prevents you from browsing some restricted sites, and the browser automatically recognizes that some sites are restricted because the Site's level is already set in the meta tag of the Site. The rating is assessed by the U.S. rsac, the Entertainment Commission ratings agency, If you need to evaluate your site, you can connect to the website http://www.rsac.org/, submit the form on request, then RSAC will provide a meta code to you, Copy it to your Page.

5. Controlling page buffering


〈meta Http-equiv=〃expires〃content=〃tue,11.nov 1998 00:00 gmt〃〉

Meta can set the time the page expires, that is, when you set the browser in Internet Explorer 4.0 to view the page in the local buffer first, then when browsing a page, and local buffering and sometimes, then the browser will automatically browse the buffer in the page, The browser will not get a new page until the time set in the meta Expires.

Properties of 6.META

Http-equiv=〃....〃http header of the response;

The name of the Name=〃.....〃meta information;

The specific content of Content=〃....〃meta information;

Diagrams of Scheme=〃...〃meta Information.



Many people overlook the powerful effect of HTML tag meta, a good meta tag design can greatly improve the likelihood that your personal site is being searched, interested, who I come to re-understand the META tag it!

The META tag is an accessible tag in the head area of the HTML language, which is located between the <HEAD> tag and the <TITLE> tag in the header of the HTML document, which provides information that is not visible to the User. Meta tags are often used to define page themes for search engine robots, or to define a cookie on a user's browser, which can be used to identify the author, format the page, annotate the content feed and keywords, and set the page to refresh itself according to the intervals you DEFINE. and set the RASC content level, and so On.

Detailed Introduction

Here are some examples and explanations of the markings.

The META tag is divided into two parts: the HTTP header information (http-equiv) and the page description information (NAME).


HTTP-EQUIV is similar to the HTTP header protocol, which responds to the browser with some useful information to help correct and accurately display the content of the Web Page. Common types of Http-equiv are:

1, Content-type and Content-language (setting of the display character Set)

Description: sets the character set used by the page to indicate that the text used by the home page is already spoken, and the browser will invoke the corresponding character set to display the page Content.

Usage: <meta Http-equiv=content-type content=text/html; Charset=gb2312>

<meta Http-equiv=content-language content=zh-cn>

Note: the META tag defines the character set used by the HTML page as GB2132, which is the GB character Code. If you replace "charset=gb2312" with "BIG5", the character set used for this page is the traditional Chinese Big5 code. When you browse some foreign sites, ie browser will prompt you to correctly display the page need to download XX language support. This is done by reading the Content-type property of the META tag of the HTML page and knowing which character set to use to display the Page. If the corresponding character set is not installed in the system, IE prompts to Download. Other languages also correspond to different charset, such as the Japanese character set is "iso-2022-jp", the Korean is "ks_c_5601".

Content-type content can also be: Text/xml and other document types;

CharSet options: iso-8859-1 (english), BIG5, UTF-8, shift-jis, Euc, koi8-2, us-ascii, x-mac-roman, iso-8859-2, x-mac-ce, iso-2022-jp, x-sjis, x-euc-jp,euc-kr, iso-2022-kr, gb2312, gb_2312-80, x-euc-tw, X-cns11643-1,x-cns11643-2 and other character sets The Content of Content-language can also be: EN, fr and other language code.

2, Refresh (refreshed)

Description: How long (in seconds) to refresh your Web page, or how long it takes to automatically link pages to other Pages.

Usage: <meta Http-equiv=refresh content=30>

<meta Http-equiv=refresh content=5; Url=http://www.downme.com>

Note: 5 of these are meant to be automatically refreshed to URL URLs after 5 seconds of Stay.

3. Expires (term)

description: Specifies the expiration time of the page in the cache and must be re-accessed on the server once the page Expires.

Usage: <meta http-equiv=expires content=0>

<meta http-equiv=expires content=wed, 1997 08:21:57 gmt>

Note: You must use the time format of gmt, or set directly to 0 (the number indicates how much time expires after).

4, Pragma (cach Mode)

Description: prevents the browser from accessing the contents of the page from the local Machine's cache.

Usage: <meta Http-equiv=pragma content=no-cach>

Note: pages are not guaranteed to be present in the cache, and each visit refreshes the Page. With this setting, visitors will not be able to browse OFFLINE.

5. Set-cookie (Cookie Setting)

Description: when a browser accesses a page, it is cached and can be read from the cache the next time it is accessed to improve Speed. Disable caching when you want visitors to refresh your ad's icon every time, or refresh your counter every Time. Usually HTML files do not need to disable caching, for the ASP and other pages, you can use the disable cache, because every time you see the page is dynamically generated on the server, the cache loses meaning. If the page expires, the saved cookie will be Deleted.

Usage: <meta Http-equiv=set-cookie content=cookievalue=xxx; expires=wednesday,

21-oct-98 16:14:21 GMT; Path=/>

Note: the time format of GMT must be Used.
HTML tag Details page tags in detail meta-detailed meta tags meta tag role
6, window-target (display Window Settings)

Description: forces the page to appear on a separate page in the current WINDOW.

Usage: <meta Http-equiv=widow-target content=_top>

Note: This property is used to prevent others from calling your page in the Frame. Content options: _blank, _top, _self, _parent.

7, Pics-label (page Rsac Rating)

Description: There is a content setting in Internet Options for IE that prevents you from browsing some restricted sites, and the limits of websites

is set by this Parameter.

Usage: <meta Http-equiv=pics-label contect=

(pics-1.1′http://www.rsac.org/ratingsv01.html '

I Gen comment ' RSACi North America Sever ' by '[email protected]'

For ' http://www.microsoft.com ' on ' 1997.06.30t14:21-0500′r (n0 s0 v0 l0) >

Note: do not set the level too high. The RSAC evaluation system provides a standard for evaluating Web site Content. Users can set up Microsoft Internet Explorer (IE3.0 or More) to exclude sites that contain pornographic and violent content. The HTML in the example above is taken from Microsoft's Homepage. The code (n 0 s 0 v 0 L 0) indicates that the site does not contain unhealthy content. Ratings are assessed by rsac, the rating agency of the American entertainment commission, if you want to learn more about the level of RSAC evaluation system, or if you need to evaluate your own website, you can visit the Rsac site:http://www.rsac.org/.

8, page-enter, page-exit (entry and Exit)

Description: This is a number of special effects when the page is loaded and paged Out.

Usage: <meta http-equiv=page-enter Content=blendtrans (duration=0.5) >

<meta http-equiv=page-exit Content=blendtrans (duration=0.5) >

Note: Blendtrans is a kind of dynamic filter that produces a fade effect. Another dynamic filter Revealtrans can also be used for page entry and exit Effects:

<meta http-equiv=page-enter Content=revealtrans (duration=x, transition=y) >

<meta http-equiv=page-exit Content=revealtrans (duration=x, transition=y) >

Duration indicates the duration of the filter effect (in Seconds)

Transition Filter Type. Indicates which effect to use, with a value of 0-23.

0 Rectangle reduction

1 Rectangle Enlargement

2 Round Zoom Out

3 Circular Enlargement

4 down to top refresh

5 Top to bottom refresh

6 Left to right refresh

7 Right-to-left Refresh

8 Vertical Blinds

9 Horizontal Blinds

10 Dislocation Horizontal Blinds

11 Dislocation Vertical Blinds

12-point diffusion

13 or so to the middle refresh

14 Middle to left and right refresh

15 middle to upper and lower

16 up and down to the middle

17 right down to top left

18 top right to bottom left

19 top left to bottom right

20 lower left to top right

21 Horizontal Bar

22 Vertical Bar

23 or more 22 random selection of a
9. Msthemecompatible (xp Theme)

Description: whether to turn off XP themes in IE

Usage: <meta http-equiv=msthemecompatible content=yes>

Note: Turn off Xp's Blue stereo button system display style, which is much like Win2k.

10. IE6 (page Builder)

Description: page Builder generator, is IE6

Usage: <meta http-equiv=ie6 content=generator>

Note: with what things to do, similar products factory Manufacturers.

11. Content-script-type (script Related)

Description: This is the latest specification of the web, indicating the type of script in the Page.

Usage: <meta Http-equiv=content-script-type content=text/javascript>


★name variable

Name is a description of the Web page, corresponding to the Content (web page contents), so that search engine robots to find, classify (currently almost all search engines use online robots automatically find meta values to classify web pages).

The value of name (name=) specifies the type of information provided. Some of the values are already defined. such as description (description), keyword (keyword), refresh, and so On. You can also specify any other value, such as: creationdate (date created),

Document ID (doc Number) and level (rank), and so On.

The content of name specifies the actual contents. For example, If the level (rank) is value (value), content may be beginner (beginner), intermediate (intermediate), advanced.

1, Keywords (keywords)

Description: a list of keywords for search engines

Usage: <meta name=keywords content= keyword 1, keyword 2, keyword 3, keywords 4,...... >

Note: Each keyword is separated by a comma ",". The usual use of meta is to specify keywords that search engines use to improve search Quality. When several meta elements provide document language dependency information, search engines use the Lang feature to filter and display search results through the User's language precedence Reference. For example:

<meta name=kyewords lang=en content=vacation,greece,sunshine>

<meta name=kyewords lang=fr content=vacances,grè:ce,soleil>

2, Description (introduction)

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

Usage: <meta name=description content= A brief description of your webpage >


3. Robots (robot Wizard)

Description: robots is used to tell the search robot which pages need to be indexed and which pages do Not. The content parameters are all, none, index, noindex, follow, nofollow. The default is All.

Usage: <meta name=robots content=all| none| Index| Noindex| follow| Nofollow>

Note: many search engines log on to websites by releasing Robot/spider search, and these robot/spider use some of the META element features to determine how to log in.

All: the file will be retrieved and the link on the page can be queried;

None: the file will not be retrieved and the link on the page cannot be queried; (and noindex, no follow play the same role)

Index: file will be retrieved; (let robot/spider log In)

Follow: links on the page can be queried;

Noindex: the file will not be retrieved, but the link on the page can be queried; (do not let Robot/spider log In)

Nofollow: the file will not be retrieved and the link on the page can be Queried. (do not let the Robot/spider follow this page to look Down)
What is meta tag meta tag usage TCP IP detailed JSP application development detailed
4. Author (author)

Description: Label the author or production group of the page

Usage: <meta name=author content= Zhang san,[email protected]>

Note: The content can be: you or your production group's name, or email

5. Copyright (copyrights)

Description: Label Copyright

Usage: <meta name=copyright content= This page belongs to NetEase academy. All Rights reserved>


6. Generator (editor)

Description: Description of the editor

Usage: <meta Name=generator content=pcdata| Frontpage|>

Note: content= The editor you are using

7. Revisit-after (re-visit)


Usage: <meta name=revisit-after content=7 days >


Some other uses in the ★head

1. Scheme (scheme)

Description: scheme can was used when name was used to specify how the value of content should be Interpreted.

Usage: <meta SCHEME=ISBN name=identifier content=0-14-043205-1/>


2. Link (links)

Description: linking to a file

Usage: <link Href=soim.ico rel=shortcut icon>

Note: Many sites if you save her in the inbox, you will find that it is accompanied by a small icon, if you click again, you will find the Address bar also has a small icon. You can now easily implement this feature by adding this to your page header. <LINK> is used to link the current file to other urls, but there is no link button for the <HEAD> tag between the following formats:

<link Href=url rel=relationship>

<link Href=url rev=relationship>

3, Base (link)

Description: Insert Web page Base Link property

Usage: <base href=http://www.***.net/target=_blank>

Note: all relative paths on your page will be prefixed with "http://www.***.com/" when Linking. Where Target=_blank is the link file opens in a new window, you can do other settings. Change "_blank" to "_parent" is the link file will open in the parent window of the current window, instead the "_self" link file opens in the current window (frame), instead the "_top" link file is displayed in full Screen.

These are some of the basic uses of meta tags, the most important of which are: keywords and description settings. Why is it? The reason is very simple, these two statements can let the search engine can find you accurately, attract more people to visit your site! according to the current popular search engine (google,lycos,altavista, etc.) work principle, search engine first sent the robot automatically on the WWW search, when the discovery of new sites, Easily retrieve keywords and description from the page and add it to your database, then sort the site by the density of the KEYWORDS.

About HTTP request Headers: HTTP-EQUIV

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