Some projects require you have a floating selvedge. Here I am using a floating selvedge the same color as the weft that I will be using. When I was just starting to weave my good friend Kay K. told me: "You enter the shed over the floating selvedge and exit under on the other side."
I have put on enough warp for several projects, so I have hung the floating selvedge off the back instead of winding it around the back with the rest of the warp. That way, when I change weft colors I can change the color of the floating selvedge too. Sometimes it just gives a better looking edge.