The Upholstery Forum

Hi All,
This might be a silly questions, but I have google searched an answer and couldn't find anything that gave m e a sound answer. Looking at the lower shank adapter on my machine, I noticed a metal spring clip on the top surface of the adapter that I have never used for any reason and I have never seen it used on any other sewing machine either. My guess is that you can insert some kind of sliding edge guide maybe? Does anyone know what the actual use for it is?

Hi Pat. I am sort of new here so I probably would not know the answer. For those with years of sewing, a machine brand and model would be useful.

Pics help too

So what I'm referring to is this metal clip that's circled in red. Any ideas what it's used for? Please see attached photo.