Name of the output file for legal notices if %generate-legalnotice-link% is true. Since several legal notices may occur (in a Set of Books, for example), this is no longer a fixed filename.
(define ($legalnotice-link-file$ legalnotice)
  ;; Name of output file for legal notices
  (if (and %use-id-as-filename% (attribute-string (normalize "id") legalnotice))
      (string-append (attribute-string (normalize "id") legalnotice)
		     %html-ext%)
      (string-append "ln"
		     (number->string (all-element-number legalnotice))
		     %html-ext%)))