Confused about pin assignment in the Spartan Edge Accelerator

Hello everyone! I was looking at the schematic file of the Spartan Edge Accelerator board, and I found many of the names of the pins unfamiliar and arcane. Is there a reference manual that describes what these are? I can infer what some of them mean, but I’m not sure how to figure out what FPGA_K4 or FPGA_AR_D13 are, for example.

The vivado tutorial on the wiki for the board has a nice example with a constraints file that uses pins for LEDs, a clock, and GPIO. This is very nice, but where and how can I inform myself of what everything else does?

I guess I’m a bit of a beginner looking for some hand-holding. Please forgive me if my questions are ignorant :slight_smile:

Thanks in advance!