$ grep -r -l org-fold- .
./org/.git/index
./org/doc/org-manual.org
./org/etc/ORG-NEWS
./org/lisp/ob-core.el
./org/lisp/ob-exp.el
./org/lisp/ob-lilypond.el
./org/lisp/ob-ref.el
./org/lisp/ol.el
./org/lisp/org-agenda.el
./org/lisp/org-archive.el
./org/lisp/org-capture.el
./org/lisp/org-clock.el
./org/lisp/org-colview.el
./org/lisp/org-compat.el
./org/lisp/org-crypt.el
./org/lisp/org-cycle.el
./org/lisp/org-element.el
./org/lisp/org-feed.el
./org/lisp/org-fold-core.el
./org/lisp/org-fold.el
./org/lisp/org-footnote.el
./org/lisp/org-goto.el
./org/lisp/org-id.el
./org/lisp/org-inlinetask.el
./org/lisp/org-keys.el
./org/lisp/org-lint.el
./org/lisp/org-list.el
./org/lisp/org-loaddefs.el
./org/lisp/org-loaddefs.el~
./org/lisp/org-macs.el
./org/lisp/org-mobile.el
./org/lisp/org-mouse.el
./org/lisp/org-refile.el
./org/lisp/org-src.el
./org/lisp/org-table.el
./org/lisp/org.el
./org/lisp/ox-org.el
./org/lisp/ox.el
./org/testing/lisp/test-org-fold.el
./org/testing/lisp/test-org-list.el
./org/testing/lisp/test-org.el