Restore Startup Hotkeys. Resets to the default hotkeys.
Store Startup Hotkeys. Use this button to save hotkeys that you want to be available when ZBrushCore starts.
Load Hotkeys File. Use this button to load a hotkeys file from disk.
Save Hotkeys File. Use this button to save a hotkeys file to disk. This might be hotkeys you have created for a specific project. For hotkeys that you want available every time ZBrushCore starts use the Store button above.