Automatically show local help on point-over.
If the value is t, the string obtained from any `kbd-help' or
`help-echo' property at point is automatically printed in the
echo area, if nothing else is already displayed there, or after a
quit. If both `kbd-help' and `help-echo' produce help strings,
`kbd-help' is used. If the value is a list, the help only gets
printed if there is a text or overlay property at point that is
included in this list. Suggested properties are `keymap',
`local-map', `button' and `kbd-help'. Any value other than t or
a non-empty list disables the feature.
This variable only takes effect after a call to
`help-at-pt-set-timer'. The help gets printed after Emacs has
been idle for `help-at-pt-timer-delay' seconds. You can call
`help-at-pt-cancel-timer' to cancel the timer set by, and the
effect of, `help-at-pt-set-timer'.
When this variable is set through Custom, `help-at-pt-set-timer'
is called automatically, unless the value is `never', in which
case `help-at-pt-cancel-timer' is called. Specifying an empty
list of properties through Custom will set the timer, thus
enabling buffer local values. It sets the actual value to nil.
Thus, Custom distinguishes between a nil value and other values that disable the feature, which Custom identifies with `never'. The default is `never'.