What Are the Different Symbols for Kosher Foods? - Delighted Cooking Cows and other cloven-hoofed, cud-chewing animals are kosher. The OU Symbol of Kosher Certification represents the Union of Orthodox Jewish Congregations, with an image of the letter "U" inside a circle. Among other symbols for kosher foods, the OU is one of the oldest, having approved of kosher products since 1923.