Default [q] smart_io.crd

Sorry for this Noob question, but I have a microSD card and I have this SMART_IO.CRD file in the root.
I see many posting referencing this same filename, and placing it in FAT32 formatted root directory, but what exactly is it?
Is it executable code, or some kind of configuration file?
Is is accessed by the bootloader or by Android?
I have searched everywhere I can think of an not found an answer to any of these

Thanks for any guidance on this.