Both (elisp) `Window Hooks' and the doc string talk about "the buffer-local part of this hook". I don't know what that means. Since when does a hook have "parts", one of which is the "buffer-local part"? Node (elisp) `Hooks' says nothing about any "local" or other "part" of a hook. Searching for "local" there finds only (1) mention that a major mode overrides buffer-local variable assignments and (2) mention that you can "You can add hooks either globally or buffer-locally". I'm really wondering what could possibly be meant by this doc. This strange language was apparently introduced in Emacs 23. I have no idea what it is trying to say. Please clarify this doc. In GNU Emacs 26.0.90 (build 3, x86_64-w64-mingw32) of 2017-10-13 Repository revision: 906224eba147bdfc0514090064e8e8f53160f1d4 Windowing system distributor `Microsoft Corp.', version 6.1.7601 Configured using: `configure --without-dbus --host=x86_64-w64-mingw32 --without-compress-install 'CFLAGS=-O2 -static -g3''