The conventions used to present command syntax in this book are the same conventions used in the IOS Command Reference. The Command Reference describes these conventions as follows:
Boldface indicates commands and keywords that are entered literally as shown.
Italics indicate arguments for which you supply actual values.
Vertical bars (|) separate alternative, mutually exclusive elements.
Square brackets [ ] indicate optional elements.
Braces { } indicate a required choice.
Braces within brackets [{ }] indicate a required choice within an optional element.