Org has in-buffer completions. Unlike minibuffer completions, which are useful for quick command interactions, Org’s in-buffer completions are more suitable for content creation in Org documents. Type one or more letters and invoke the hot key to complete the text in-place. Depending on the context and the keys, Org will offer different types of completions. No minibuffer is involved. Such mode-specific hot keys have become an integral part of Emacs and Org provides several shortcuts.
Complete word at point
org-tag-alist(possibly set through the
#+TAGSin-buffer option, see Setting tags), or it is created dynamically from all tags used in the current buffer.
#+STARTUP:, complete startup keywords.
If your desktop intercepts the combo M-TAB to switch windows, use C-M-i or ESC TAB as an alternative or customize your environment.