From http://www.w3schools.com (Copyright Refsnes Data)

HTML <link> tag

Example

Link to an external style sheet:

The <link> tag defines the relationship between a document and an external resource.

The <link> tag is most used to link to style sheets.

When used for style sheets, the <link> tag is supported in all major browsers. No real support for anything else.

In HTML the <link> tag has no end tag.

In XHTML the <link> tag must be properly closed.

Note: The link element must be embedded in the head section, and it can appear any number of times.

DTD indicates in which DTD the attribute is allowed. S=Strict, T=Transitional, and F=Frameset.

Attribute	Value	Description	DTD
charset	char_encoding	Specifies the character encoding of the linked document	STF
href	URL	Specifies the location of the linked document	STF
hreflang	language_code	Specifies the language of the text in the linked document	STF
media	screen tty tv projection handheld print braille aural all	Specifies on what device the linked document will be displayed	STF
rel	alternate appendix bookmark chapter contents copyright glossary help home index next prev section start stylesheet subsection	Specifies the relationship between the current document and the linked document	STF
rev	alternate appendix bookmark chapter contents copyright glossary help home index next prev section start stylesheet subsection	Specifies the relationship between the linked document and the current document	STF
target	_blank _self _top _parent frame_name	Specifies where the linked document is loaded	TF
type	MIME_type	Specifies the MIME type of the linked document	STF

id, class, title, style, dir, lang, xml:lang

For a full description, go to Standard Attributes.

onclick, ondblclick, onmousedown, onmouseup, onmouseover, onmousemove, onmouseout, onkeypress, onkeydown, onkeyup

For a full description, go to Event Attributes.