1 /ALL
/ALL /NOALL (default) Delete all messages shown by the last DIRECTORY command. When used in conjunction with the /CHANNEL qualifier, only those messages shown by the last DIRECTORY command for the specified channel will be deleted. Unless /NOCONFIRM is specified with /ALL, you will be required to confirm any DELETE/ALL operation.
2 /CHANNEL
/CHANNEL=name Specifies the name of the channel from which to delete messages. Wildcards are not permitted.
3 /CONFIRM
/CONFIRM /NOCONFIRM (default) When /CONFIRM is specified, you will be prompted to confirm each message delete operation.
4 /LOG
/LOG (default) /NOLOG Specifies whether informational messages for each message delete operation are generated.