Package: org-mode cus-test.el suggests the following variables may have incorrect custom :types. (There may be some false positives.) This refers to Org mode in current Emacs trunk.
Eg, org-footnote-auto-adjust does not have "nil" as an option. org-refile-target-verify-function org-icalendar-combined-description org-link-frame-setup org-export-with-archived-trees org-bibtex-prefix org-log-note-headings org-structure-template-alist org-export-html-postamble-format org-get-priority-function org-export-odt-content-template-file org-export-latex-quotes org-export-html-toplevel-hlevel org-agenda-ndays org-export-initial-scope org-plantuml-jar-path org-export-blocks-witheld org-make-link-description-function org-export-html-postamble org-babel-lob-files org-agenda-export-html-style org-clock-heading-function org-show-notification-handler org-agenda-custom-commands org-beamer-outline-frame-options org-agenda-day-face-function org-use-fast-tag-selection org-export-docbook-xsl-fo-proc-command org-link-translation-function org-export-docbook-xslt-stylesheet org-export-docbook-xslt-proc-command org-columns-modify-value-for-display-function org-export-html-preamble-format org-agenda-auto-exclude-function org-export-docbook-doctype org-wl-namazu-default-index org-agenda-inactive-leader org-export-ascii-underline org-sparse-tree-default-date-type org-footnote-auto-adjust org-protocol-default-template-key