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- What is it?
- The Link tag is a stand alone element using many of the same
attributes as the Hyperlink tag [A].
It indicates a relationship between the document and some other object.
A document may have any number of LINK elements which can indicate
authorship, related indices and glossaries, older or more recent
versions, document hierarchy, associated resources such as
style sheets, etc. Servers may also allow links to be added by those who do
not have the right to alter the body of a document.
The popular browsers are just beginning to support this tag, which has been in
the HTML specifications for some time.
- Some uses for LINK
Many of the following keywords are taken from the expired HTML 3.0
Draft. They describe a proposed standard set of relationships for use
in documents. Details of browser support and examples are further down.
REL=Bookmark
- These are used to provide direct links to key entry points into an
extended document. The TITLE attribute may be used to label the bookmark.
Several bookmarks may be defined in each document, and provide a means for
orienting users in extended documents.]
- REL=Copyright
- References a copyright statement for the current document.
- REL=Help
- References a document offering help, e.g. describing the wider context
and offering further links to relevant documents. This is aimed at reorienting
users who have lost their way.
- REL=Glossary
- References a document providing a glossary of terms that pertain to
the current document.
- REL=Home
- References a home page or the top of some hierarchy.
- REL=Index
- References a document providing an index for the current document.
- REL=Next
- References the next document to visit in a document structure or guided tour.
- REL=Previous
- References the previous document in a document structure or guided tour.
- REL=StyleSheet
- References an external Style
Sheet which is used to control the way the current document
is rendered.
- REL=ToC
- References a document serving as a table of contents.
- REL=Up
- If the document is part of a hierarchy, this references the
immediate parent of the current document.
Defining document specific toolbars
- [ IE | M3 | N ]
- The LINK element can be used to define a toolbar of navigation buttons
or an equivalent mechanism such as menu items. Many of the values for the
REL attribute could be reserved for this purpose (such as Home, Next, Previous,
etc.)
- Example:
<link TITLE="Here is my home page" REL="HOME" HREF="myhome.htm">
Link to an associated Style Sheet
- [ IE3B1 | M | N4B2 ]
- The LINK element can be used with REL=StyleSheet to reference an external
Style Sheet which is used to control the way the current document is rendered.
- Example:
<link REL="STYLESHEET" HREF="http://www.company.com/mystyles.css"
TYPE="text/css">
- Attributes
- Href
- 2 | 3
| 3.2 | IE3B1
| M3 | N4B2
- Required? No
- Description:
- This attribute indicates the URL of a document linked to the current
document through relationships established by the other attributes of
this tag.
- Values: Relative or absolute URLs.
- Rel
- 2 | 3
| 3.2 | IE3B1
| M3 | N4B2
- Required? No
- Description:
- The REL attribute is meant to give the relationship(s) described between
the current document and the document specified by the HREF attribute.
- Values: A whitespace separated list of relationship names.
- Rev
- 2 | 3
| 3.2 | IE3B1
| M3 | N4B2
- Required? No
- Description:
- The REL attribute is basically meant to be the same as the REL
attribute, but the semantics of the relationship are in the reverse
direction. A link from A to B with REL="X" expresses the
same relationship as a link from B to A with REV="X".
A LINK tag may have both REL and REV attributes.
- Values: A whitespace separated list of relationship names.
- Title
- 2 | 3
| 3.2 | IE
| M3 | N4B2
- Required? No
- Description:
- This attribute suggests a title (advisory only) for the destination
resource indicated by the LINK HREF attribute. The TITLE attribute
may be used for display prior to accessing the destination resource
(such as in a margin note or in a pop-up box while the mouse is over
the hyperlink), or for resources that do not include titles (like
graphics, plain text documents or Gopher menus.)
- Values: Alphanumeric string value.
- Type
- 2 | 3
| 3.2 | IE3B1
| M | N4B2
- Required? No
- Description:
- This attribute appears to have been created by Internet Explorer for
use in their implementation of linked external Style Sheets. No
official reference exists for this attribute other than an
implementation example at Microsoft's Style Sheet reference tutorial.
It APPEARS to represent the MIME type of the Style Sheet
document.
- Values: text/css,
text/javascript
- Example
- <html>
<head>
<title>Document
Title</title>
<link
TITLE="Here is my home page"
REL="HOME"
HREF="myhome.htm">
<link
REL="STYLESHEET"
HREF="http://www.company.com/mystyles.css"
TYPE="text/css">
</head>
<body>
Document content goes here.
</body>
</html>
- Parent Model
- <head>
- Content Model
- This tag accepts no content.
Tips & Tricks
- The Mosaic implementation is not widely supported yet, even though
many of the concepts for it have been proposed in HTML since version
2.0. Its use does not harm a document in any way, but it would be best
not to rely on this as a sole navigation scheme until wider support
exists.
- Remember to use the TYPE attribute in relation to the use of the LINK
tag for Style sheet purposes. With the advent of Netscape's Javascript
Accessible Style Sheets, it never hurts to be explicit as to which
style sheet language is being used.
- The implementation of Style Sheets has begun with Internet Explorer 3.0
and has continued with its debut in Netscape version 4.0. These browsers
represent a fair amount of the total browser market, so its use is not
discouraged.
Browser Peculiarities
- Mosaic supports the LINK tag beginning in its 3.0 versions.
All LINK REL navigation relationships will be rendered in a seperate
pane of the browser window (it sounds like the original idea for a
common navigation bar.)
- Internet Explorer 3.0 Beta 1 did not automatically register the
MIME type for Style Sheets, so if you're using a linked style sheet,
the server administrator on the user's site would have to register the
"text/css" type on the server (there may be a work-around
for this - See the TYPE attribute to the LINK tag above.) This problem
was fixed in later Internet Explorer versions.
- Netscape 4.0 Beta 2 assumed a default MIME type for style sheets
to be 'text/javascript' for Javascript accessible style sheets. This was
fixed in beta 3 to the accepted 'text/css' default.
Boring Copyright Stuff...