Efficacy of HTML-head-meta

Definition

Send hidden information about the document to the server and client.

Note

The meta element also embeds the document information used by some search engines to index and classify documents on the World Wide Web.

This element can only be used within the head element.

This element is available in HTML of Internet Explorer 3.0 and later versions, and in scripts of Internet Explorer 4.0 and later versions.

This element is not displayed.

The label does not need to be disabled for this element.

Meta is used to simulate HTTP Response Header packets in HTML documents.
Meta Tags are used in Meta has two attributes: Name and HTTP-equiv. The name attribute is mainly used to describe webpages,
Corresponds to content (web content), which facilitates search engine robot searching and Classification
(Currently, almost all search engines use online robots to automatically search for Meta values to classify webpages ).
The most important one is description (the description of the site on the search engine)
And keywords (classification keyword), so you should add a meta value to each page.
The following name attributes are commonly used:

1. <meta name = "generator" contect = ""> describes generation tools (such as Microsoft FrontPage 4.0;

2. <meta name = "keywords" contect = ""> describe keywords Of Your webpage to search engines;

3. <meta name = "Description" contect = ""> tell the search engine the main content of your site;

4. <meta name = "author" contect = "Your name"> tell the search engine the creator of your site;

5. <meta name = "Robots" contect = "All | none | index | noindex | follow | nofollow">

The attributes are described as follows:

Set to all: the file will be retrieved, and the link on the page can be queried;

Set to none: files will not be retrieved, and links on the page cannot be queried;

Set to index: the file will be retrieved;

Set to follow: links on the page can be queried;

Set to noindex: the file will not be retrieved, but the link on the page can be queried;

Set to nofollow: files will not be retrieved, and links on the page can be queried.

HTTP-equiv attributes

1. <meta http-equiv = "Content-Type" contect = "text/html"; charset = gb_2312-80 ">

And <meta http-equiv = "content-language" contect = "ZH-CN"> to describe the text and language used by the homepage;

Also such as English is the ISO-8859-1 character set, there are big5, UTF-8, shift-JIS, EUC, Koi8-2 and other character sets;

2. <meta http-equiv = "refresh" contect = "N; url = http: // yourlink"> regularly redirect a webpage to the HTTP: // yourlink;

3. <meta http-equiv = "expires" contect = "mon, 12 May 2001 00:20:00 GMT"> you can set the expiration time of a webpage, once it expires, it must be called again on the server. Note that the GMT time format must be used;

4. <meta http-equiv = "Pragma" contect = "no-Cache"> is used to disable the browser from accessing the page content from the cache of the local machine, once the page is set, it cannot be called out from the cache;

5. <meta http-equiv = "Set-cookie" contect = "mon, 12 May 2001 00:20:00 GMT"> cookie setting: If the webpage expires, the cookie on the disk will be deleted. Note that the GMT time format must be used;

6. <meta http-equiv = "pics-label" contect = ""> webpage rating: There is a content setting in Internet Options of IE, it can prevent browsing of some restricted websites, and the website's restricted level is set through the meta attribute;

7. <meta http-equiv = "Windows-target" contect = "_ top"> force the page to be displayed on an independent page in the current window, it can prevent your webpage from being called as a frame page by others;

8. <meta http-equiv = "Page-Enter" contect = "revealtrans (duration = 10, Transtion = 50) "> and <meta http-equiv =" Page-Exit "contect =" revealtrans (duration = 20, Transtion = 6) "> set the special effect when you enter and exit the page, this function is called "format/Webpage transition" in FrontPage, but the page to be added cannot be a frame page.