HEKHSHER (Heb. הֶכְשֵׁר; "approbation" or "attestation"), certificate issued by the rabbinate or by individual rabbis certifying that a certain food product has been prepared under their supervision and in accordance with the traditional dietary *laws, hence declaring it kasher. Such an attestation is also required for all foodstuff prepared for consumption on *Passover in which case it must also be free from all leaven (*ḥameẓ). The hekhsher certificate is now usually printed on the package of the product. Restaurants which are under the supervision of a rabbinate need a hekhsher (which is displayed on the premises), testifying that the food served by them is prepared in accordance with the traditional dietary laws and that a *mashgi'aḥ oversees the kitchen. In some countries specific symbols have been adopted to indicate that the product is under supervision. The Union of Orthodox Hebrew Congregations in the U.S. uses (a "u" inside an "O" – U nion of O rthodox) and in that country there is also widespread use of various other kashrut supervising bodies that employ the letter "K", alone or in combination with other communally recognized symbols. In England the seal of the bet din is used. In certain states of America it is illegal to declare a product kasher if it is not, but for observant Jews that does not obviate the need for a rabbinic hekhsher.