Controls that have a click action associated with them, such as cmd, may define an accelerator character by inserting a "&" in front of the desired character in the display text of the control. For example, if a button displays "Open", you can make the "O" be the accelerator character by setting the label to "&Open." Such an accelerator character allows the control to be "clicked" by the key combination alt+<char> where <char> is the designated accelerator character. (In the example just described, hitting Alt+O would act the same as clicking on the button.)

Accelerator characters will be indicated on the screen by underlining, although the underlines may not initially appear until the user hits the Alt key.

Note that in order for the accelerator to have a practical effect, the control must define some kind of action in its cmd parameter and its ctype flags must include MBF_KBD.