If you find something in your version of the Maya FBX Plug-in that does not appear in the documentation, consult the readme file that accompanied the plug-in. The readme will contain last-minute changes to the software that are not reflected in the documentation.
It is also possible that your version of the Maya FBX Plug-in may not be the most recent version. It is a good practice to check for updates, as each subsequent Maya FBX Plug-in version has enhanced functionality, and is available free. See for instructions on how to verify that your plug-in version is the latest.