That is a WinRT MIDI device identifier.
SWD: Software Device
MMDEVAPI: Our MIDI 1.0 in-box API device enumerator
MIDIII_B…: MIDI Input and the hash of the Id that the USB stack provides us
P.0002: device pin # 2
{guid}: Interface Id for MIDI 1.0 Input Ports
If the device does not have a USB serial number implemented, the number can change based on which USB port you plug into, if you use a hub, etc. Windows tries to use the same number each time, but some manufacturers make this more difficult.
I wrote this a couple years ago, and have been socializing it with device companies. Although we’ve tried to make some things easier, this problem doesn’t go away with the new MIDI stack.
Not a problem unique to Windows either. macOS and other operating systems jump through similar hoops trying to retain device ids. It gets especially complex if there’s more than one of the same device, and they don’t have serial numbers.
Pete
Microsoft