The Command List
The command list contains a list of commands that can be applied to expressions in the document. To open the Command list, select Command List from the View menu or press Shift + F8. This window can be docked or remain free floating.
Commands are organized into groups. This is done to allow using the same shortcut key for more than one command. There are enough commands so that it would be difficult to assign a unique shortcut key to every command. Only the shortcut keys from the current group are active, so the shortcut keys can be reused.
In most cases, the Standard commands group is the current group. The only time one of the other groups is active is when you select a command group using either its shortcut key (typically a capital letter) or when you click on the command group in the Command List view. When a command group is selected, the commands in that group are shown in the top section of the command list view and the shortcut keys for those commands are active. When a command from the group is selected, the active command group will switch back to the Standard commands.
As a result, the commands in groups other than the Standard command group are activated by entering two shortcut keys in succession. For example, if you have x highlighted and want to put a bar over it you need the "Hat" options command. This command is in the Convert group so the shortcut keys are "C" and then "h". In the example files, you will see commands like this indicated as "Hat" options (C, h).