When the spacebar auto complete function is enabled, pressing the spacebar after a CLI command fragment will allow you to determine if the fragment is unique. If it is, the CLI will complete the fragment on the current display line.
By default, this function is disabled. For more information on enabling it using the set cli completion command, refer to CLI Properties Configuration Commands. The following example shows how, when the function is enabled, entering conf and pressing the spacebar would be completed as configure:
System(rw)->conf<SPACEBAR> System(rw)->configure