access key or accesskey
Definition
The accesskey HTML attribute is a method by which web page authors can embed keyboard shortcuts to specific elements on their page that users can jump to using the access key and shortcut combination from their keyboard... Implementations vary by browser, but modern browsers have largely standardized on Ctrl-Option-key on the Mac and Alt-Shift-key on Windows, where key is the accesskey code for a particular element specified by the page author. Although not enforced, access key codes are usually limited to numeric digits 0-9 to keep things simple and avoid confusion related to caps and lower-case.