[STANDBY] DATABASE 
[{ UNTIL { CANCEL | TIME date | CHANGE integer }
 | USING BACKUP CONTROLFILE 
 } 
 [ UNTIL { CANCEL | TIME date | CHANGE integer }
 | USING BACKUP CONTROLFILE 
 ]...
]

For information on the symbols and conventions of Backus-Naur Form (BNF) syntax, see Appendix A.