I wen’t to the HID Global product site and didn’t see any mention of GY…
I have never hear of it before, and may have missed it on the site 
Do you have a Proxmark3, Flipper or similar?
if not
This may not work anyway, but can you try and scan your HID card with TagInfo
and a photo if possible.
Plus if you have a flashlight, can you shine it behind the card and take a photo of the antenna location.