Linting

:Org lint [checker ...]  Check the buffer for syntax mistakes (Emacs
                        org-lint) and list the problems in the location
                        list (title "org-lint", entries "checker: message",
                        E for high trust, W for low trust). With checker
                        names (completed), only those run (Emacs C-u C-u).
                        No default key, as in Emacs. In the location list
                        window, as in Emacs's report buffer: h hides the
                        reports of the checker under the cursor, i also
                        ignores that checker when refreshing
                        (org-lint--ignore-checker), r lints again
                        (Emacs g, which Vim needs for gg and the other
                        g commands).

Lua: require("org.lint").lint(bufnr, checkers?) returns the reports { lnum, col, checker, message, trust } sorted by position, and require("org.lint").show(checkers?) fills the location list. The buffer is parsed like Org's element parser, so messages and lines match Emacs.

Checkers (low trust ones are heuristics):
  misplaced-heading (low)           ** Heading glued to text
  duplicate-custom-id               duplicate-name   duplicate-target
  duplicate-footnote-definition
  orphaned-affiliated-keywords (low) #+NAME: / #+ATTR_*: with no element
  combining-keywords-with-affiliated (low)
                                    keyword right above affiliated ones
  obsolete-affiliated-keywords      #+TBLNAME:, #+SRCNAME:, #+RESULT:
  deprecated-export-blocks (low)    #+BEGIN_HTML instead of BEGIN_EXPORT
  deprecated-header-syntax (low)    #+PROPERTY: cache yes, :cache:
  missing-language-in-src-block     suspicious-language-in-src-block (low)
  missing-backend-in-export-block   invalid-babel-call-block
  wrong-header-argument             wrong-header-value (low)
  empty-header-argument (low)       named-result
  deprecated-category-setup         second #+CATEGORY: keyword
  invalid-coderef-link              invalid-custom-id-link
  invalid-fuzzy-link                invalid-id-link (current buffer, then
                                    the ID locations, see org-id)
  trailing-bracket-after-link (low)
  unclosed-brackets-in-link-description (low)
  link-to-local-file (low)          non-existent-setupfile-parameter (low)
  wrong-include-link-parameter (low) obsolete-include-markup (low)
  unknown-options-item (low)        misspelled-export-option (low)
  invalid-macro-argument-and-template (low)
  special-property-in-properties-drawer
  obsolete-properties-drawer        invalid-effort-property
  invalid-id-property               undefined-footnote-reference
  unreferenced-footnote-definition  extraneous-element-in-footnote-section
  invalid-keyword-syntax (low)      invalid-image-alignment
  invalid-block (low)               mismatched-planning-repeaters (low)
  misplaced-planning-info (low)     incomplete-drawer (low)
  indented-diary-sexp (low)         quote-section (low)
  file-application                  percent-encoding-link-escape (low)
  spurious-colons                   non-existent-bibliography
  missing-print-bibliography        invalid-cite-export-declaration
  incomplete-citation (low)         item-number
  priority                          LaTeX-$ (low)
  beamer-frame (low)                timestamp-syntax (low)
  clock-syntax (low)                planning-inactive
  LaTeX-$-fragment                  $...$ fragments; only on request:
                                    Emacs registers it under the name
                                    LaTeX-$, which the ambiguous-$ checker
                                    replaces

Differences from Emacs:

• suspicious-language-in-src-block knows the languages Babel can run (babel.languages) and those with a Vim filetype, instead of Emacs major modes.
• Header arguments of the languages shipped with Org (python, shell, C, sqlite, ...) are accepted as if their ob- library were loaded.
• misplaced-heading reports the line of the heading; Emacs sometimes reports a later line.
• Link and file checks use the plugin's link abbreviations, link types, attachment directories (org-attach) and ID locations.
• Nothing is skipped: every checker of Org 9.8 is implemented. The report buffer's keys are in the location list: h hides and i ignores a checker, r (Emacs g) lints again.