Many kosher certifiers also specify details pertinent to the kosher status of the item being certified.
Here are some key examples:
Kosher for Passover: A “P” often indicates that the item is kosher to be consumed on Passover, when no chametz (grain which has risen) is allowed.
Meat, Dairy and Parve: Sometimes (but not always), the agency may indicate whether the food item is meat, dairy or parve (neutral). This is important since the kosher laws preclude eating or serving dairy together with meat. A “DE” indicates that the item was processed on diary equipment but does not contain actual dairy ingredients.
Pat Yisrael and Chalav Yisrael: At times, the label may indicate whether or not the item is pat Yisrael (baked by a Jew) and/or chalav Yisrael (milk that has been produced under Jewish supervision).
Mevushal: There are certain laws that pertain to wine but are not applicable if the wine has been cooked. Cooked wine is often labeled as mevushal.
Glatt: The word glatt actually means “smooth” in Yiddish, and refers to the lack of adhesions on the lungs of an animal.