I put this ledge at the bottom of my cups which is a hangover from wood firing our train where I needed to get the wads under the cup so that the ash deposit( camel sneeze or walrus snot) didn't melt down and cover the wad or drip down onto the kiln shelf. Sheila said that my bottom was getting too big and I needed to put some shape into it. She cut an undulating line around the foot which I think relates to the band I have started to put on the cup. The band which I reference to beer barrels I like to make wavey and it is much more interesting than a straight line. Come to Tony's Fat Camp and shave weight off your bottom is my new slogan.