The U Symbol on Food — OU Kosher Explained
The U inside a circle on a package is the Orthodox Union kosher mark. This page covers what plain OU means, how the suffixes D, DE, M, Fish and P change it, and the labeling rule you can verify with your own eyes.
It is the Orthodox Union
The mark is a capital U inside a circle, and the circle is a letter O. Together they read OU, for Orthodox Union, the largest kosher certifying agency. On a package it means the Orthodox Union approved that product’s ingredients, inspected the plant and licensed the company to print the mark on that item. It is the Union’s registered certification trademark, used under license and withdrawable.
Plain OU, with nothing after it
An OU on its own means the product is kosher and pareve: neither meat nor dairy, and not made with either. That is the default, and it covers most of a packaged grocery aisle.
What the letters after it change
| Mark | Means |
|---|---|
| OU | Kosher and pareve |
| OU-D | Dairy, or made on dairy equipment |
| OU-DE | No dairy ingredients, but produced on equipment that had run dairy |
| OU-M, OU Glatt | Meat |
| OU-Fish, OU-F | Contains fish ingredients |
| OU-P | Kosher for Passover and pareve. The P is Passover, never pareve |
The labeling rule you can check yourself
The Orthodox Union’s labeling requirements are specific and visible to a shopper. The suffix must sit next to the mark in type the same size as the mark, not as a subscript and not shrunk, so a D you have to squint at is a warning sign. The mark has to be printed as part of the package artwork rather than rubber-stamped or applied on a sticker, because anything removable can be moved to an uncertified package. Where the mark is allowed to sit is covered on kosher symbols on food packaging.
A circled U is not a bare U
The shape is the point. A U inside a circle is an owned design with an organization behind it, a public list of certified products, and a legal route against misuse. A bare U or a bare K printed flat on a package belongs to nobody, because a single letter cannot be held as a trademark. Some companies that print a naked K really are supervised. Others decided for themselves. There is no way to read which from the letter. Other agency marks, including the circled K of OK Kosher and the starred K of STAR-K, are listed in the kosher food symbols list.
There is no OU character to paste
Unicode has no codepoint for the OU mark or any other kosher agency design. Whatever circled letter turns up in a character map is a different character that happens to resemble it, and typing it does not reproduce the mark. What travels as text is the string OU-D, four ordinary characters that paste cleanly into any field, any spreadsheet and any username box. Printing the actual design on a product the Orthodox Union has not certified is trademark infringement. The general mechanism is explained on what are kosher food symbols.