Provide metadata to pages and sites |
WAI / WCAG 1.0 Priority 2 checkpoint 13.2
Issue Description The page does not contain, in its HEAD section, any LINK element that specifies relations between this page and other documents or information items. For example, use RDF to indicate the document's author, the type of content, etc. Some HTML user agents can build navigation tools from document relations described by the HTML LINK element and "rel" or "rev" attributes (e.g., rel="next", rel="previous", rel="index", etc.).
How to fix Consider adding LINK elements to the HEAD section to represent relationships between this page and other documents. The list of possible relationships between documents that can be represented by the LINK element from HTML 4.01 Specification [http://www.w3.org/TR/html401/types.html#type-links] .
Issue Explanation The LINK element defines a link that is not shown to the user, but it is used by the browser for special purposes. It conveys information that the browser can process in several ways (for example Mozilla can display a special navigation bar; lynx presents these links in a special section of its display).

In general LINK represents a relationship between the current document and something else. An example is the relationship between the current HTML document and an external CSS file. Another example is to represent the next and previous document in a sequence of documents (like for different chapters in a tutorial).

Consider the following example by the W3C (HTML 4.01 Specification [http://www.w3.org/TR/html401struct/links.html#h-12.3] ):

    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
       "http://www.w3.org/TR/html4/strict.dtd">
    <HTML>
    <HEAD>
      <TITLE>Chapter 2</TITLE>

      <LINK rel="Index" href="../index.html">
      <LINK rel="Next"  href="Chapter3.html">
      <LINK rel="Prev"  href="Chapter1.html">
    </HEAD>
    ...the rest of the document...

In the following example, also taken from the same source, the HREFLANG attribute to tell search engines where to find Dutch, Portuguese, and Arabic versions of a document. Note the use of the CHARSET attribute for the Arabic manual. Note also the use of the LANG attribute to indicate that the value of the title attribute for the LINK element designating the French manual is in French.

    <HEAD>
    <TITLE>The manual in English</TITLE>
    <LINK title="The manual in Dutch"
          type="text/html"
          rel="alternate"
          hreflang="nl"
          href="http://someplace.com/manual/dutch.html">
    <LINK title="The manual in Portuguese"
          type="text/html"
          rel="alternate"
          hreflang="pt"
          href="http://someplace.com/manual/portuguese.html">
    <LINK title="The manual in Arabic"
          type="text/html"
          rel="alternate"
          charset="ISO-8859-6"
          hreflang="ar"
          href="http://someplace.com/manual/arabic.html">
    <LINK lang="fr" title="La documentation en Fran&ccedil;ais"
          type="text/html"
          rel="alternate"
          hreflang="fr"
          href="http://someplace.com/manual/french.html">
    </HEAD>

In the following example, search engines are told where to find the printed version of a manual.

    <HEAD>
    <TITLE>Reference manual</TITLE>
    <LINK media="print" title="The manual in postscript"
          type="application/postscript"
          rel="alternate"
          href="http://someplace.com/manual/postscript.ps">

    </HEAD>

And here where to find the front page of a collection of documents.

    <HEAD>
    <TITLE>Reference manual -- Page 5</TITLE>
    <LINK rel="Start" title="The first page of the manual"
          type="text/html"
          href="http://someplace.com/manual/start.html">

    </HEAD>