Shortcut Keys

Shortcut keys (also referred to as accelerator keys) are keys or key combinations that, when pressed, provide quick access to frequently performed operations. CTRL+letter combinations and function keys (F1 through F12) are usually the best choices for shortcut keys. By definition, a shortcut key is a keyboard equivalent of functionality that is supported adequately elsewhere in the interface. Therefore, avoid using a shortcut key as the only way to access a particular operation.

Note
Function key and modified function key combinations may be easier for international users because they have no mnemonic relationship. However, there is a tradeoff because function keys are often more difficult to remember and to reach. For a list of the most common shortcut key assignments, see Appendix B, "Keyboard Interface Summary."

When defining shortcut keys, observe the following guidelines:

• Assign single keys where possible because these keys are the easiest for the user to perform.
• Make modified-letter key combinations case insensitive.
• Use SHIFT+key combinations for actions that extend or complement the actions of the key or key combination used without the SHIFT key. For example, ALT+TAB switches windows in a top-to-bottom order. SHIFT+ALT+TAB switches windows in reverse order. However, avoid SHIFT+text keys, because the effect of the SHIFT key may differ for some international keyboards.
• Use CTRL+key combinations for actions that represent a larger scale effect. For example, in text editing contexts, HOME moves to the beginning of a line, and CTRL+HOME moves to the beginning of the text. Use CTRL+key combinations for access to commands where a letter key is used — for example, CTRL+B for bold. Remember that such assignments may be meaningful only for English-speaking users.
• Avoid ALT+key combinations because they may conflict with the standard keyboard access for menus and controls. The ALT+key combinations — ALT+TAB, ALT+ESC, and ALT+SPACEBAR — are reserved for system use. ALT+number combinations enter special characters.
• Avoid assigning shortcut keys defined in this guide to other operations in your software. That is, if CTRL+C is the shortcut for the Copy command and your application supports the standard copy operation, don't assign CTRL+C to another operation.
• Provide support for allowing the user to change the shortcut key assignments in your software, when possible.
• Use the ESC key to stop a function in process or to cancel a direct manipulation operation. It is also usually interpreted as the shortcut key for a Cancel button.

Some keyboards also support three new keys, the Application key and the two Windows keys. The primary use for the Application key is to display the pop-up menu for current selection (same as SHIFT+ F10). You may also use it with modifier keys for application-specific functions. Pressing either of the Windows keys — left or right —displays the Start menu. These keys are also used by the system as modifiers for system-specific functions. Do not use these keys as modifiers for nonsystem-level functions.