It works on almost any menu; not just right click context menu. XCode for example, is much more useful when you realize you learn that half of the menu options you really want are hidden by holding down the option key.

The WiFi icon has an insane amount of information if you option click it for example... (most of the system ones do)

Holding option in menus, settings, or while clicking the status bar is easily the most underused and under-documented feature of MacOS... (maybe after removing annoying shit with launchctrl).

Edit: totally didn't see the two other posts with exactly the same tip, ha. Maybe not so underused -_-;