kill-buffer-hook

kill-buffer-hook is a variable defined in `files.el'.
Its value is

(erc-kill-buffer-function reftex-kill-buffer-hook save-place-to-alist tramp-delete-temp-file-function browse-url-delete-temp-file uniquify-kill-buffer-function vc-kill-buffer-hook)

• This variable's value is permanent if it is given a local binding.
• This variable may be risky if used as a file-local variable.

Documentation:
Hook run when a buffer is killed.
The buffer being killed is current while the hook is running.
See `kill-buffer'.

Note: Be careful with let-binding this hook considering it is
frequently used for cleanup.