Other issues to watch out for when food, wax, etc. is attached to the part where there is no letters, numbers, etc.
Sweeping the Staircase, the Floor of the Sukkah, and Sweeping a Rubber Mat;
Trying On Freshly Laundered Clothing for the Nine Days;
improving the Ground through SOSSAIR, Carpet Removal, SOSSAIR in Conjunction with a Faucet Filter, and Anything Related to Kitchen Cabinets;