The best way to set a key to do nothing

Question

My touchpad occasionally issues [mouse-12] events which results in annoying flickering and a repeating <mouse-12> is undefined message.

According to elisp conventions, what is the best way to do nothing?

(global-set-key [mouse-12] 'WHAT-TO-INSERT-HERE?)

Answer 1

That would be the ignore function:

ignore is an interactive compiled Lisp function in ‘subr.el’.

It is bound to <mouse-movement>, <bottom-divider> <mouse-1>,
<right-divider> <mouse-1>.

(ignore &rest IGNORE)

Do nothing and return nil.
This function accepts any number of arguments, but ignores them.

If it's good enough for the mouse-movement event, it should be good enough for the touchpad:

(global-set-key [mouse-12] 'ignore)