{ { BACKUPPIECE | PROXY } 
  { 'media_handle' [, 'media_handle']... 
  | primary_key [, primary_key]... 
  | TAG [=] ['] tag_name [']
  }
| BACKUPSET primary_key [, primary_key]...
| { CONTROLFILECOPY | DATAFILECOPY }
  { { primary_key [, primary_key]... 
    | 'filename' [, 'filename']...
    } 
  | TAG [=] ['] tag_name ['] [, ['] tag_name [']]...
  }
| ARCHIVELOG
  { primary_key [, primary_key]... 
  | 'filename' [, 'filename']...
  }
}