Unloaded files are removed from the list when XTrkCad terminates.
Files can be listed by either their file name or by their internal description. This is controlled by the Show File Names check box.
The Browse button allows you to load other Parameter Files such as provided by other users or by Sillub Technology.
When first installed, all available parameter files are loaded. You can unload parameter files you don't use to speed up XTrkCad startup time.
The order in this list controls the order of Turnouts and Structures on the Hot Bar. You can move a Parameter File to the end of the list by Unloading it, and then loading it via the Browse button.