What is the '245' in the IOKit USB libraries?

Question

I'm getting started with IOKit on OS X, and I've been puzzled by the '245' tagged onto data types in the IOKit USB library, such as IOUSBInterfaceInterface245. What does the 245 mean? I'm just curious what this number tacked onto the end is supposed to indicate. It seems like a version number of something.

Is there a generic version that I can use, rather than having to use a specific version?

Answer 1

I believe that number refers to the IOUSBFamily version the struct is compatible with. Take a look at IOKit/usb/IOUSBLib.h for more details.