The Autodesk MotionBuilder preset is used for exporting animation files to MotionBuilder.Use the Autodesk MotionBuilder preset if you are using a Maya to MotionBuilder back to Maya workflow. This preset uses the Constraints and Skeleton defintions as options set for optimal Character animation using Maya and MotionBuilder.
If you change a preset, the preset field displays User defined, to show that the preset differs from its default state. The plug-in saves the User defined state in a temporary file so that the settings are the default the next time you use the plug-in.
You can also use save your settings as a custom preset. See Creating a custom preset.