★ Major authority
Circular MK-style rabbinical seal
USA
CIRC
Mark: Circular seal with intertwined Hebrew/Latin lettering
Recognized endorsed by 1 major authority
COR
Regional
Circular seal on back of COR Kosher Symbol Card; exact agency not confirmed.
How to use this safely: a listing here is not an endorsement. Only trust an authority if one you (or your community) already follow recognizes it — see the “endorsed by” tags above. Standards vary by community and by individual ruling, so always confirm with your rav.