Depending on the Switch model and the code version, the manifest.txt file may not work. You have to be on a 7000 series switch and at least 8.0.40 code to recognize the manifest. I created this document that may be helpful as well.
Also worth noting that the documentation is wrong regarding configuration downloads as well. It does request multiple configuration files: * hostnameMAC-config.cfg * hostnameMAC.cfg * hostname.cfg * brocade.cfg But it stops after the first one. Claims that subsequent files are appended to the configuration are not true.