BYOC Tremolo Schematic vs Parts List

[swinginguitar]

The parts list shows a 180 ohm resistor, and there's a spot for it on the PCB, but I don't see it listed on the schematic. What does it do and where is it located in relation to the schematic?

(not building the kit - building it from parts on hand but don't see it on the schematic...am I overlooking it?)