Variable: org-html-footnote-separator
org-html-footnote-separator is a customizable variable defined in
ox-html.el.gz.
Value
"<sup>, </sup>"
Documentation
Text used to separate footnotes.
Source Code
;; Defined in /usr/src/emacs/lisp/org/ox-html.el.gz
(defcustom org-html-footnote-separator "<sup>, </sup>"
"Text used to separate footnotes."
:group 'org-export-html
:type 'string)