A required choice within an optional element. Both mean hold down the Control key while you press the D key. Keys are indicated in capital letters, but are not case sensitive. A string A nonquoted set of characters. For example, when setting an SNMP community string to public , do not use quotation marks around the string, because the string will include the quotation marks.
System prompts Denotes interactive sessions, indicates that the user enters commands at the prompt.
The system prompt indicates the current command mode. Nonprinting characters, such as passwords. Comments are sometimes displayed by the Cisco IOS software. Caution Means be careful . In this situation, you might do something that could result in equipment damage or loss of data.