This command loads the MotionBuilder presets provided with each release.

You can use this to load the MotionBuilder Import/Export presets without knowing their file path.

For example: FBXLoadMBExportPresetFile; loads "C:\maya2012\bin\plug-ins\FBX\Presets\2012.0\export\Autodesk MotionBuilder.fbxexportpreset" (The path may be different on your machine.)