The CLEAR CIRCUIT command resets circuit parameters in the volatile
 database to the default value (if any), or removes them from the volatile
 database on the local node or DTE.
 The PURGE CIRCUIT command always removes circuit parameters from the
 permanent database on the local node or DTE.
 CLEAR   KNOWN CIRCUITS        (parameters...)
         CIRCUIT circuit-id
 All underscores found in parameters must be replaced with spaces when
 parameters are used in NCP commands.
Additional Information:
explode
extract