BYOC Spring Reverb Instructions Manual page 24

Step 2: Install the footswitch. Orient the footswitch so that the flat sides of
the solder lugs are like the diagram below.
NOTE: There are no actual number markings on the footswitch. There are
two correct ways you can orient the footswitch. They are both 180 degrees
of each other. Either way is fine. It does not matter as long as the flat sides
of the solder lugs are running horizontal, not vertical.
NOTE: It may be easier to wire up the foot switch before installing it into
the pedal. There will be more room to work & it will be much easier to
thread the lug 4 to lug 9 jumper.