114 Using the Command-Line Interface
You can also enter a question mark (?) after typing one or more characters of a 
word to list the available command or parameters that begin with the letters, 
as shown in the following example:
console#show po?
policy-map       port                     ports
Using Command Completion
The CLI can complete partially entered commands when you press the 
<Tab> or <Space> key. 
console#show run<Tab>
console#show running-config
If the characters you entered are not enough for the switch to identify a single 
matching command, continue entering characters until the switch can 
uniquely identify the command. Use the question mark (?) to display the 
available commands matching the characters already entered.
Entering Abbreviated Commands
To execute a command, you need to enter enough characters so that the 
switch can uniquely identify a command. For example, to enter Global 
Configuration mode from Privileged EXEC mode, you can enter con instead 
of configure.
console#con
console(config)#
Negating Commands
For many commands, the prefix keyword no is entered to cancel the effect of 
a command or reset the configuration to the default value. Many 
configuration commands have this capability.