Wouldn't gbak complain about unknown parameters?

I'm not able to connect to the database server right now so I can't run
gbak -help, but the manual at firebirdsql.org states:

-G[ARBAGE_COLLECT) inhibit garbage collection


Disclaimer: This message (including attachments) is confidential and may be privileged. If you have received it by mistake please notify the sender by return e-mail and delete this message from your system. Any unauthorized use or dissemination of this message in whole or in part is strictly prohibited. Please note that e-mails are susceptible to change. RxStrategies, Inc. shall not be liable for the improper or incomplete transmission of the information contained in this communication or for any delay in its receipt or damage to your system. RxStrategies, Inc. does not guarantee that the integrity of this communication has been maintained nor that this communication is free from viruses, interceptions or interference.