The difference between one letter or two letters; writing with a "SHINUI" (not the usual manner).
One letter on top of another letter.
Pickling Foods, Salting Foods: Is One Allowed to Put Back a Pickle into Its Jar Which Was Taken Out?;
הכנה ליום אחר (Preparations for a Weekday): The Basic Halachas of Washing Dishes and Glasses;