 .DOCTITLE
  \E*[$DOC_TYPE]       &mdash;the NAMED argument passed to .DOCTYPE
  \E*[$AUTHOR]         &mdash;the current first argument passed to .AUTHOR
  \E*[$AUTHOR_1...9]   &mdash;the current arguments passed to .AUTHOR
  \E*[$AUTHORS]        &mdash;a comma-separated concatenated string
                          of all the current arguments passed to .AUTHOR
                          (i.e. a list of authors)
  \E*[$CHAPTER_STRING] &mdash;the current argument passed to .CHAPTER_STRING,
                  