1. <meta> element provides meta-information about the page (meta-information), such as for search engines and the frequency of updating the description and keywords. <meta> tag at the head of the document does not contain any content.
2. Properties <meta> tag defines the name associated with the document / value pairs.
3. Common Code:
<meta http-equiv="content-Type" content="text/html; charset=gb2312" > <meta http-equiv="X-UA-Compatible" content="IE=edge" />； <meta name ="keywords" content="science,education,culture,politics,ecnomics,relationships,entertainment,human">
That is: <meta> tag is always located inside the head element. Metadata is always delivered in the form of name / value pairs.
4.meta label contains two properties, which are http-equiv and name attributes, different attributes have different parameter values, these different parameter values to achieve a different page functions.
A. Name attribute
The name attribute is used to describe the main
page
, the corresponding
attribute value
for the content, the content of the main content is to facilitate the search engine robots to find information and the classification information.
meta tag name attribute syntax is: <meta name = "parameter" content = "a specific parameter value"> ;.
Where the name attribute are the following parameters:
A, Keywords (keywords)
Description: keywords used to tell
the search engines
what keywords your page might be.
举例：<meta name ="keywords" content="science,education,culture,politics,ecnomics,relationships,entertainment,human">
B, description (site description)
Description: description used to tell the search engine the main content of your website.
Website content description (description) design features:
① website described as a natural language rather than a list of keywords (keywords and design just the opposite);
② describe the core content of the page as accurately as possible, usually web content summary information, the summary information is hope that search engines display in the search results;
③ page description comprising an effective keyword;
④ web page description and title content highly correlated;
⑤ web page description and body content highly correlated;
⑥ page text description need not be too much, generally no more than a search engine search results
summary
maximum word information (usually within 100 characters, the different search engines slightly different).
举例：<meta name="description" content="This page is about the meaning of science,education,culture.">
C, robots (robot wizard)
Description: robots used to tell search robots which pages to index, which does not require an index page.
content parameters are all, none, index, noindex, follow, nofollow. The default is all.
举例：<meta name="robots" content="none">
D, author (Author)
Description: As the name suggests (labeled page author)
Two. Http-equiv attribute
http-equiv name suggests, the equivalent of the http header action, it may return some useful information to the browser to help correct and accurate display Web content, the corresponding attribute value content, the content is actually the content of each parameter
variable value
.
http-equiv meta tag attribute syntax is: <meta http-equiv = "parameter" content = "variable value parameter">; wherein http-equiv attribute parameters are the following:
A, Expires (period)
Note: You can set the expiration time for the web page. Once the website expired, must be re-transmitted to the server.
用法：<meta http-equiv="expires" content="Fri,12 Jan 2001 18:18:18 GMT">
Note: You must use the time format GMT.
B, Pragma (cache mode)
Description: Prevents the browser from the local computer's
cache
to access the page content.
用法：<meta http-equiv="Pragma" content="no-cache">
Note: this setting, visitors will not be able to browse offline.
C, Refresh (refresh)
Description: automatic refresh and go to the new page.
Usage: <meta http-equiv = "Refresh" content = "2; URL">; (note the semicolon, respectively in front of and behind the seconds URLs, URL may be empty)
Note: two of which refers to the automatic refresh URL address to stay after 2 seconds.
D, Set-Cookie (cookie settings)
Note: If the page expired, then archiving the cookie will be deleted.
用法：<meta http-equiv="Set-Cookie" content="cookievalue=xxx; expires=Friday,12-Jan-2001 18:18:18 GMT; path=/">
Note: You must use the time format GMT.
E, Window-target (display setting window)
Description: Forces the page is displayed in a separate page in the current window.
用法：<meta http-equiv="Window-target" content="_top">
Note: to prevent other people to call its own page in the framework.
F, content-Type (Display Character Set)
Description: Set pages use the character set.
用法：<meta http-equiv="content-Type" content="text/html; charset=gb2312">
G, content-Language (the language setting of the display)
用法：<meta http-equiv="Content-Language" content="zh-cn" />
Features
Above us some of the basic components of meta tags, then let's take a look at the meta tags of common features:
Help Home is registered major search engines
A very important feature is to set meta tags keywords to help your home be the major search engines login, increase traffic to the site. In this function, the most important thing is to set Keywords and description. Because, according to how search engines work, search engine first sent robots to automatically retrieve pages of keywords and description, and add it to your database, and then under the keyword density of the site will be sorted. Therefore, we must set up keywords to improve search click-through rate of the page. Let's give an example for your reference: <meta name = "keywords" content = "politics, economy, science and technology, culture, health, emotional, spiritual, entertainment, lifestyle, social, business, transportation">
<Meta name = "description" content = "politics, economy, science and technology, culture, health, emotional, spiritual, entertainment, lifestyle, social, business, transportation">
After setting these keywords, the search engine will automatically add them to the database, and ordered according to the appropriate density of these keywords.
Custom page language
This is the most common meta tags function in the production of web pages, we will see it in pure HTML code, which is to define the role of the language of your web page, when visitors access your web browser will automatically recognize and set up a web page language, if your page is set GB code, but the viewer is not installed GB code, then the web browser will render the viewer set the default language. Similarly, if the page is in English, then charset = en. The following is a representative example:
<meta http-equiv=″content－Type″ content=″text/html; charset=gb2312″>
The code says that the language of the webpage is set to GB code.
Automatically refresh and point to the new page
If you want to make your pages without human control, can automatically within the specified time to access specified web page, you can use meta tags to automatically refresh the page. Here we look at a piece of code:
〈meta http-equiv=″refresh″ content=″2; URL=
This code can be automatically transferred to the current one web page to go after 2 seconds, which is the role of meta refresh in content, the time represents the set (in seconds), and the URL that is specified time web page addresses automatically connected.
Animation
Use meta tags, we can also be animated in the moment to enter or leave the web page, as long as we in the html code of the page in the <head> </ head>; add the following code between the tags on it:
<meta http-equiv="Page-Enter" content="revealTrans(duration=5.0,transition=20)">
Once the above code is added to a Web page, and then we will see when the page out of some special effects, this feature is actually the same as FrontPage2000 the Format / Page Transition, but we have to note that the page can not be added to a Frame pages; RevealTrans Reveals dynamic
filter
Duration indicates the duration of filter effects (unit: seconds)
Transition filter types. It indicates what type of effects used a value of 0-23:
0 narrow rectangle
1 rectangle expand
2 narrow circular
3 Round expand
4 down to refresh
5 to the next refresh
6 left-to-right Refresh
7 refresh Right to Left
8 vertical
blinds
9 horizontal louver
Offset horizontal louver 10
11 dislocation vertical blinds
12:00 diffusion
About 13 to refresh the intermediate
About 14 to refresh the intermediate
15 intermediate the upper and lower
16 down to the intermediate
17 lower right to upper left
18 top right to bottom left
19 top left to bottom right
20 lower left to upper right
21 bar
22 bars
More than 22 kinds of 23 randomly choose one
Grading evaluation page
IE4.0 above version of the browser can prevent some websites restricted, and the reason why the browser will automatically recognize some of the site is restricted, it is because the site meta tags have been set up in the level of the site, and the level assessment by the United States RSAC, namely entertainment committee of rating agencies, if you need to evaluate your own website, submit the form as required, then the RSAC will provide some meta code that you copied to your pages in it. Here is a code sample:
〈meta http-equiv=″PICS－Label″
content=′（PICS－1.1
l gen true comment ″RSACi North America Server″
for
on ″2001.08.16T08:15－0500″
r (n 0 s 0 v 0 l 0））′〉
Control paged
You can set the page meta tags due time, that is, when you set browsing in Internet Explorer browser to view the local cache of the first page, then when browsing a web page, and have a local buffer, then the browser the buffer will automatically browse the pages, the time until the meta set to expire, at this time, the browser will go to get a new page. For example, the following code represents the expiration time on the web page 2001 at 18:18:18 on on January 12.
Control page window
We can also use meta tags to control page display window, the following code is added as long as the page on it: <metahttp-equiv = "window-target" content = "_ top"> ;, page code may be prevented others as a Frame call.
Other uses
scheme (scheme)
说明：scheme can be used when name is used to specify how the value of content should
be interpreted.
Translation scheme to be used for specifying the attribute value. This scheme should be defined in the profile attribute specified by <head> tag profile file.
用法：<meta scheme="ISBN" name="identifier" content="0-14-XXXXXX-1" >
Link (Link)
Description: Link to File
用法：<Link href="soim.ico" rel="Shortcut Icon">
Note: Many sites if you store it in the inbox, you will find that even with a small icon, if you click to re-enter the address bar will also have found a small icon. Now just in your head plus page these words, you can easily achieve this function. <LINK> URL for the file for the other link, but no link button, for <HEAD> tag between the following format:
<link href="URL" rel="relationship">
<link href="URL" rev="relationship">
Base (base links)
Description: Insert web-based link properties
Note: All relative path on your pages will be added with URL in front at link time. Where target = "_ blank" is linked files open in a new window, you can do other settings. The "_blank" to "_parent" is a link file will be opened in the parent window of the current window; to "_self" link opens the file in the current window (frame); to "_top" link file full screen.
Use
Meta tags are used to describe a language web properties, a standard search engine Meta tags can facilitate sorting, improve search engine ranking website weight. Want to make the site more in line with standard search engines must understand the meta tags, Xi margin below the Seoer tell us something about the meaning and use of meta tags:
keywords
META tag
keywords of
Written as: <meta name = "Keywords" content = "parameter message">
Keywords meta tag information of the parameters, representatives explain what the site keyword yes.
Description
Description META tag
Written as: <meta name = "Description" content = "parameter message">
meta tags
Description of the parameter information, the representative of the key elements of the site, what profiles yes.
Content-Type
META tag http-equiv = Content-Type content = "text / html
http-equiv = Content-Type is represented by the head of HTTP protocol, message browser page,
Written as: <meta http-equiv = "Content-Type" content = "text / html; charset = parameter information">
When charset parameter information such as meta tags GB2312 (or GBK), representative of the coding site is described using the simplified Chinese;
Charset meta tag information parameters such as the time BIG5, on behalf of your site is coded using a traditional Chinese;
Charset meta tag information parameter as iso-2022-jp, the site is described on behalf of coding using the Japanese;
When charset parameter information such as meta tags ks_c_5601, representative of the coding site is described using the Korean;
When charset meta tag information parameter as ISO-8859-1, representative of the coding site is described in English is used;
Charset meta tag information parameters such as UTF-8, the representatives of the world's universal language coding.
NOTE: In the HTML5, when expressed charset information can be abbreviated, the foregoing contents can be removed, i.e., is written: <meta charset = "GBK"> [1]
generator
generator META tag
Written as: <meta name = "generator" content = "parameter message" />
generator meta tag information parameters, representatives explain what the software used in the production site.
author
author META tag
Written as: <meta name = "author" content = "parameter message">
author of the meta tag information parameters, explained on behalf of the copyright page of information.
⒍META tag http-equiv = "Refresh"
Written as: <Meta http-equiv = "Refresh" Content = "Time; Url = URL parameters">
How much time Refresh meta tag pages automatically refresh representatives, together with the URL parameters Url on behalf of, how long automatic links to other web site.
Pragma
HTTP-EQUⅣ META tag = "Pragma" CONTENT = "no-cache"
写法为：<META HTTP-EQUⅣ="Pragma" CONTENT="no-cache">；
Prohibition on behalf of the browser to access the page content from the cache on the local computer, so setting, visitors will not be able to browse offline.
COPYRIGHT
COPYRIGHT META tags
Written as: <META NAME = "COPYRIGHT" CONTENT = "parameter message">
COPYRIGHT meta tag information parameters, on behalf of the website description copyright information.
imagetoolbar
META tag http-equiv = "imagetoolbar"
写法为：<meta http-equiv="imagetoolbar" content="false" >
Specifies whether to display the Picture toolbar, when the representative is false does not display when the display is a true representative.
Content-Script-Type
META tags Content-Script-Type
写法为：<Meta http-equiv="Content-Script-Type" Content="text/javascript">
W3C Web Content Accessibility Guidelines, specify the type of script pages.
revisit-after
META tags revisit-after
写法为：<META name="revisit-after" CONTENT="7 days" >
revisit-after on behalf of the site revisit, 7 days represents the seven days, and so on.
Robots
Robots META tag
Written as: <meta name = "Robots" content = "parameter message">
Robots representative told which pages the search engines robots crawl
Where the property
Information parameters all: the file will be retrieved, and the links on the page can be inquiries;
Information parameter is none: document will not be retrieved, and the links on the page can not be queried;
Information parameters for the index: files will be retrieved;
Information parameters as follow: a link on the page can be inquiries;
Information parameters noindex: document will not be retrieved, but the links on the page can be inquiries;
Information parameters nofollow: document will be retrieved, but the link on the page can not be queried;
Tag optimization
Content meta tag optimization will likely become a site hits obtain the most critical content, how to better optimize the meta-tag content?
1, the monitoring range of refinement;
2, the establishment of a dynamic page titles and meta descriptions;
3, monitor your Google Webmaster About this site;
4, including your unique value proposition;
5, written by the user, not a robot.
English prefix
Prefix pref.
⒈ said, "Change", "transformation"
⒉ means "after", "after ..."
⒊ means "beyond"
⒋ means "in between ...", "between"
5. is "about that, higher level" means in the logic
Sample words: metaphysics, Metamathematics (indicates a high level of mathematical philosophy)
n.
⒈ metaphysics; metaphysics
⒉ esoteric reasoning; talk; short theory
From the Greek, the original source as Aristotle's book "Metaphysics," a book's title, which means "first philosophy", it is "as there is the presence of (being as being)" for the study of metaphysics, its meaning is "after specific scientific."
Template meta language
Template meta language proposed by the GDMO, using BNF syntax is similar, so similar to ASN.1, if we can understand that it is different from the ASN.1 can be used correctly on the basis of knowledge of the ASN.1. Accordingly, here only the relevant elements described as follows:
⒈ semicolon (;) to terminate the suspension structure and templates
⒉ spaces, blank lines, comments and end of the line only as delimiters role. A need to mark the end of the element, another element used at the start.
⒊ Note the double hyphen (-) guided encounter another end of the line, or double hyphen terminated. It can appear in any separate area, but can not appear in a space between the name of the structure or template name contains.
⒋ square brackets ([]) indicate optional elements for template definition.
⒌ the right asterisk in parentheses (*) indicate an optional element template definition.
⒍ select an object by a pipe | split (). This symbol is intended to define the support member in use.
⒎ determined character string by the user in the spread angle brackets (<>;) in.
⒏ attachment with a reference numeral, followed by the symbol - >> ;, then after a string of text and grammar symbols defined by the composition.
⒐ delimited string appears in the form of natural language text or description in text in the template definition. They from an arbitrary strings, a string can be terminated by the separator guide and any of the following. Delimiter is "$% ^ & *` '~ @ \. " If the separator string started by a delimiter, then the same again separated string until it encounters the separator until the end.
Original Address: https://blog.csdn.net/katara1109/article/details/49157139