Cases when food, drinks, wax, etc. fell in an area where there is NO letters, numbers, pictures.
working with items that are made to go in and out on a constant basis;
Understanding the Concept of Inflatable Items on Shabbos;
understanding the two views with "דרך לכלוך" (coloring destructively). (Wiping one's hands on a towel from grape juice, blood, pomegranate, colored ices, etc.);