Unlike the a element (informally called a link when it contains an href attribute), the link element belongs inside the head element and is a place for the document to establish links with external documents, such as style sheet definition files or font definition files. By and large, browsers have yet to exploit the intended powers of this element. A variety of attributes let the author establish relationships between the current document and potentially related documents. In theory, some of these relationships could be rendered as part of the document or browser controls. Implementations of this element as of Version 6 of Navigator and Internet Explorer are rather weak compared to the HTML 4 specification. At the same time, several attributes (and all event handlers) defined in the HTML 4 specification and listed among shared items at the beginning of this chapter aren't very helpful because they more typically apply to elements that actually display content on the page. No explicit document content is rendered as a result of the link element. Some of those attributes may be associated with the link element by mistake or merely for consistency.

Character encoding of the content at the other end of the link.

Boolean switch that enables or disables the user's ability to activate or otherwise access an element. This attribute is limited to interactive form control elements in Netscape 6 and HTML 4. IE 5.5 and later (Win32 only) also applies this attribute to most other renderable elements. Disabled elements are usually "greyed out" to distinguish themselves from other elements.

The URI of the document associated with the link (also known in W3C jargon as the destination, even though there is no page navigation involved). Navigator 4 uses the src attribute for this purpose. Include both attributes for a backward-compatible implementation.

The language code of the content at the destination of a link. Requires that the href attribute also be set. This attribute is primarily an advisory attribute to help a browser prepare itself for a new language set if the browser is so enabled.

The language being used for the element's attribute values and content. A browser can use this information to assist in proper rendering of content with respect to details such as treatment of ligatures (when supported by a particular font or required by a written language), quotation marks, and hyphenation. Other applications and search engines might use this information to aid the selection of spell-checking dictionaries and the creation of indices.

Sets the intended output device for the content of the destination document pointed to by the href attribute. The media attribute looks forward to the day when browsers are able to tailor content to specific kinds of devices such as pocket computers, text-to-speech digitizers, or fuzzy television sets. The HTML 4 specification defines a number of constant values for anticipated devices, but the list is open-ended, allowing future browsers to tailor output to yet other kinds of media and devices.

Defines the relationship between the current element and the destination of the link. The HTML 4 recommendation defines several link types; it is up to the browser to determine how to employ the value. The element must include an href attribute for the rel attribute to be applied.

A reverse link relationship. Like the rel attribute, the rev attribute's capabilities are defined by the browser, particularly with regard to how the browser interprets and renders the various link types available in the HTML 4 specification. Given two documents (A and b) containing links that point to each other, the rev value of b is designed to express the same relationship between the two documents as denoted by the rel attribute in A. Version 6 browsers provide no practical functionality for this attribute.

The URL of the destination of a link. Internet Explorer 4 and later, Netscape 6, and HTML 4 use the href attribute for this purpose. Include both attributes for a cross-browser implementation.

Presumably, the target attribute is provided in HTML 4 as a way to specify the destination for the display of a document at the other end of the href attribute of the link element.

An advisory about the content type of the destination document or resource. In practice, this attribute has been used so far to prepare the browser for the style sheet type being linked to.