These require additional input. The router will give you the options available for the rest of the command, and will place the default option in brackets. For example, from the Priveledged mode, to get the the global configuration mode (config mode) you will type: config t (config terminal) – but if you just type config, the following will be shown:
Router# config
Configuring from terminal, memory, or network [terminal]?
If you hit <Enter> the default selection will be made (terminal). You can also type the name of the option or just the first letter and hit enter (for network option, type “n <enter>”)
<TAB> key (for example, for “sh history”, type in “sh his <TAB>”