how to omit section numbers from theindex.html when publishing a project

["Christopher W. Ryan" <cryan@binghamton.edu>]

Well, my IT department did some major damage to my computer system, and
now the output of publishing a project (my only one) to html is
different. Specifically, the numbers next to each alphabetical letter in
theindex.html are shown, whereas before they were not. I can't recall if
this is some sort of setting that I changed once and now need to change
back. How can I prevent thos numbers from appearing in theindex.html,
but still have them appear in the main document for which theindex.html
is the index?

Emacs 26.2 on Windows 10 professional.

Relevant portion of .emacs:

;; Projects and publishing
;;
(setq org-publish-project-alist
      '(("CaseInvestigationTrainingAndReferenceManual"
         :base-directory
"E:/DATA/BCHD/CD/ChinaCoronavirus2019/CommCare/TrainRef/"
         :publishing-directory
"E:/DATA/BCHD/CD/ChinaCoronavirus2019/CommCare/TrainRef/StagingArea"
	 :publishing-function org-html-publish-to-html
	 :base-extension org
	 :makeindex t)))

Thanks.

--Chris Ryan