what are cyclone3 RUP3 and RDN3 pins?

The cyclone3 pinouts include pins RUP3 and RDN3 but their nature and function are not described anywhere that I can see. I'm looking in the pinout document for the cyclone3 FPGA I am designing with (EP3C5), and at the end of that document where all the pins are described, RUP3 and RDN3 are not listed or mentioned. I also searched the cyclone3 handbook (the big PDF document) and got no matches. What are these signals, and why are they not described anywhere (these names are in the "optional functions" column).