In-buffer settings

  #+TITLE: #+AUTHOR: #+DATE: #+EMAIL:   export metadata
  #+SETUPFILE: "path/to/shared.org"     import file settings recursively
  #+TODO: / #+SEQ_TODO: / #+TYP_TODO:   keyword sequences (replace config)
  #+TAGS: work(w) home(h) { @a @b }     tag list, fast keys and groups
  #+FILETAGS: :proj:                    tags inherited by every entry
  #+CATEGORY: name                      category in the agenda
  #+STARTUP: overview content showall showeverything nofold
             show2levels .. show5levels hidedrawers nohidedrawers
             hideblocks nohideblocks
             indent noindent hidestars showstars entitiespretty
             entitiesplain num nonum odd oddeven
             fnlocal fnauto fnprompt fnconfirm fnplain fnanon
             fnadjust nofnadjust fninline nofninline
             logdone lognotedone nologdone logrepeat nologrepeat
             logreschedule nologreschedule logredeadline ...
             lognoteclock-out nolognoteclock-out logdrawer nologdrawer
             logstatesreversed nologstatesreversed
             customtime (custom timestamp display)
             linkpreviews nolinkpreviews inlineimages noinlineimages
             latexpreview nolatexpreview (org-images)
             shrink noshrink (table columns with width cookies)
  #+PROPERTY: NAME value                file-wide property; NAME+ appends
  #+PROPERTY: header-args:python :results output
  #+COLUMNS: %25ITEM %TODO %Effort{:}   column view format
  #+CONSTANTS: tax=0.16                 constants for table formulas
  #+TBLFM: $3=$1*$2                     table formulas (org-tblfm)
  #+PLOT: title:"x" ind:1               plot options (org-plot)
  #+ORGTBL: SEND name orgtbl-to-latex   radio table (org-radio-tables)
  #+ARCHIVE: file::* Heading            archive location
  #+LINK: gh https://github.com/%s      link abbreviation
  #+PRIORITIES: A E C                   highest, lowest, default (or
                                        numbers 0-64: 1 10 5)
  #+OPTIONS: toc:2 num:nil ^:{}         export options
  #+INCLUDE: "file.org"   #+MACRO: name text $1

After editing a #+ line, press <C-c><C-c> on it to refresh the buffer.

Local setup files #+SETUPFILE: "path/to/shared setup.org" imports core file settings as well as export settings. Nested paths resolve relative to the referring file; quotes allow spaces. Only settings are imported, so headings and line numbers in the current document stay unchanged. Cycles stop at the repeated file; repeated imports outside a cycle are allowed. Imports are bounded to 64 nesting levels and 256 imports per parse.

Paths expand ~ but not environment variables (Emacs expand-file-name). Settings are collected in directive order. ARCHIVE, COLUMNS and PRIORITIES use the first value. CATEGORY is the buffer's own last #+CATEGORY, else the first one collected (org-element--get-category). Column view prefers the buffer's own first non-empty #+COLUMNS line (org-columns-get-format). Cached document metadata refreshes when setup dependencies change, appear, disappear, or have unsaved edits in a loaded buffer. A URL is downloaded as resource_download_policy allows (org-remote-resources, like #+INCLUDE:), once a session: "prompt" asks the first time the file is read (with no UI to ask in, such as a headless Neovim, only safe_remote_resources URLs are fetched), and a refused or failed download isn't tried again. Missing or unreadable local setup files are ignored; lint reports missing paths.