Concept
The tag provides metadata about the HTML document. Metadata will not be displayed on the page, but will be machine parsable.
Action
Meta elements are typically used to specify page description, keywords, author of the document, last modified, and other metadata.
Composition
meta tag has two property that http-equiv and name.the syntax like taht:
<meta name="params" content="something you want to show" />
name
keywords
for purpose of search engine optimization
<meta name="keywords" content="your web keywords" />
description
due to tell web engine your website content
<meta name="description" content="your web main content" />
viewport
in common use on mobile
- params
<meta name="viewport" content="width=device-width, initial-scale=1, user-scalable=no" />
robot
tell spiders the index whether need
- params:
- none: the search engine will ignore page, be equivalent to noindex, nofollow
- noindex: the search engine will ignore page, be equivalent to noindex, nofollow
- nofollow: the search engine will ignore page, be equivalent to noindex, nofollow
- all: the search engine will word for page, contain page links
- index: the search engine will word for page, not contain page links
- follow: the search engine will word for page links, not contain page
<meta name="viewport" content="width=device-width, initial-scale=1" />
author
be used for label the author
<meta name="author" content="author@xxx.com" />
generator
be used for indicate program tool
<meta name="generator" content="visual studio code and so on" />
copyright
copyright message
<meta name="copyright" content="copyright message" />
revisit-after
tell spider revisit after define time
<meta name="revisit-after" content="7 days" />
renderer
define the render style of yonah browser
<meta name="revisit-after" content="7 days" />
http-equiv
http-equiv is equivalent to doc title of http
<meta http-equiv="params" content="specific descript">
content-Type
define the render style of yonah browser
<meta charset="utf-8" />
X-UA-Compatible
define the render style of yonah browser
<meta charset="utf-8" />
cache-control
control cache expire time
- params:
- no-cache: send request to server, then comnfirm web source whether already modify
- no-store: send request every time
- public: cahce all request
- private: a few of user will cache source
- maxage: cache can be use by time interval
<meta http-equiv="cache-control" content="no-cache">
expires
control cache expire time
<meta http-equiv="cache-control" content="no-cache">
refresh
<meta http-equiv="refresh" content="2；URL=http://www.lxxyx.win/">
Set-Cookie
<meta http-equiv="Set-Cookie" content="name, date" />
<meta http-equiv="Set-Cookie" content="User=Lxxyx; path=/; expires=Sunday, 10-Jan-16 10:00:00 GMT">
