footnote

Hypertext links in HTML (draft)

      FOOTNOTE
         The FOOTNOTE relationship identifies a footnote.

         When REL=FOOTNOTE is specified on an A element, the anchor is a
         footnote marker and the target is a footnote. This can be used
         to link from the footnote marker (or a highlighted word,
         phrase, etc.) to an HTML document which contains the footnote
         text, or to a portion of the same document (see REV=FOOTNOTE).

         When REL=FOOTNOTE is specified on a LINK element, it can
         specify a hypertext link to a set of footnotes which are
         related to the current document, or to a set of end-notes.

         When REV=FOOTNOTE is specified on an A element, the anchor is a
         footnote; that is, the actual content of the footnote, as
         opposed to a footnote marker. In this case, the target
         specified by the HREF value, if any, is the footnote marker.

         It has been suggested that the combination of REV=FOOTNOTE and
         NAME=...  on an A element may be used to imply that the
         enclosed content not be rendered until a link to it is
         explicitly traversed, at which time it can be presented in a
         popup window. This would allow for the inclusion of footnote
         text within a document that would not be visible until the
         reader wanted it to be presented. Developers of user agents are
         free to experiment with  this proposed feature, but there is no
         requirement that it be implemented.