<Link> a tag defines the relationship between the current document and other documents in the Web set. The link element is an empty element that contains only attributes. This element can only exist in the head part, but it can appear any number of times. In HTML, the <link> tag has no ending tag. In XHTML, the <link> label must be properly disabled.
In addition to the standard and common attributes of HTML, the link element also includes many optional attributes: charset, href, hreflang, media, rel, rev, target, title, and type. In these attributes, target can only be used in the Transitional and Frameset DTD, and others can be used in the Strict, Transitional, and Frameset DTD.
Among these attributes, the rel attribute is the core and can be used by search engines to obtain more information about links.
(1)Stylesheet-- Call an external style sheet
This attribute is the most commonly used to call a style sheet, as shown below:
<Link rel = "stylesheet" href = "http://blog.yunlives.com/style.css" type = "text/css" media = "screen"/>
Href indicates the URL of the target document, type specifies the MIME type of the target URL, and media specifies the device on which the document will be displayed.
Media: ["screen": indicates the display device; "print": indicates the printing device;].
(2)Icon-- Define the favorites icon of a website
<Link rel = "shortcut icon" href = "http://blog.yunlives.com/images/favicon.ico" type = "images/x-icon"/> <link rel = "icon" href = "http://blog.yunlives.com/images/favicon.png" type = "images /png "/>
Icon attribute specifies the title bar, address bar, and favorite bar icons
Note: 1. IE only supports favicon in ico format; 2. The rel attribute must contain cut to be displayed under IE;
(3)Canonical-- Specify the standard version of the website
<Link rel = "canonical" href = "http://blog.yunlives.com? Page = 3/"/>
The canonical attribute is used to let the search engine know the duplicate or similar webpage in the current website. The website owner wants to capture and include the webpage.
(4)Author-- Declare the author of the document
(5)Home-- Connect to the home page of the site
(6)Search-- Search tools linked to documents
(7)Sidebar-- Link to the document that should be displayed in the browser sidebar
(8)Friend-- Links
Reference link:
Http://www.cnblogs.com/aNd1coder/archive/2012/05/30/2526359.html
Http://www.dreamdu.com/xhtml/attribute_rel/
Http://www.w3school.com.cn/jsref/prop_anchor_rel.asp
<Link> detailed description of label rel attributes