If your RTF document contains footnotes or endnotes, the filter will place the text of the footnote in a separate HTML document. At the footnote reference mark, the filter will generate a hypertext link to the text of the footnote. This works with either automatically numbered footnotes[1], or user supplied footnote reference marks[+]
If you insert index entries into your RTF-document and give rtftohtml the -x-option, rtftohtml will generate a hypertext'ish index for the generated HTML-documents. Note that when using NCSA-Mosaic as your Web browser you should also tell rtftohtml to insert some text into the generated anchors by using the command line switch -X text (see section Command line options).