Hechsher

rabbinical product certification for items (foods etc.) that conform to halakha

A hechsher (/hɛxʃər/; Hebrew: הֶכְשֵׁר [ˈheχʃeʁ] "prior approval"; plural: hechsherim) is a symbol placed on food bought at a grocery store that is considered kosher by a professional kosher checker. It is usually a "U" with a circle around it.