Access keys are keyboard shortcuts for the main links used on this website.
How the keys work varies between platforms and browsers. Most browsers support jumping to specific links by typing the keys defined on the web site.
As a rule, on Windows, you can press ALT + an access key.
On a Mac (OS X), you can press Ctrl + alt (option) + an access key, pressing the enter key will follow a link.
Press Esc to close this pop up.