gus · set
Definition: a bracket strengthening an angle of a structure.
Some of the fishbone kits have a gusset that helps strengthen the nose during shipping and the early construction stages. The gusset is NOT part of the finished board and is only there to prevent the desired rocker from flattening when the bottom panel is attached. The gusset can be removed removed after you have added at least 5 rail strips but I usually just remove it after the rails are done and I am adding the solid blocking.
If you are building with a CNC fishbone kit or plans the trim line for the gusset is either machined or marked with a line. It is easiest to use a flexible Japanese Saw and saw away the bulk of the waste and then use a small plane or spokeshave to remove the last bit of material. If your saw does not flex simply cut angled cuts to remove some of the material and clean up the final bit with a plane or spokeshave.