Ptasie Mleczko (Polish) is a soft chocolate-covered candy filled with soft meringue (or milk soufflé). In Russian it is called ptichye moloko (птичье молоко) and in Romanian lapte de pasăre. All these names literally mean "bird's milk" or crop milk, a substance somewhat resembling milk, produced by certain birds to feed their young. However, this is not origin of the name; rather, ptasie mleczko is also a Polish idiom meaning "an unobtainable delicacy" (compare English: "hen's teeth"; also, a similar idiom can be found in Bulgarian – тук/там и от пиле мляко има, meaning "even bird milk can be found here/there"). In Poland it is one of the most recognized chocolate confectionery having exclusive rights in Poland for the name — other confectionery producers also make similar candies but named differently (e.g. Alpejskie mleczko, "Alpine milk"). Nonetheless, Ptasie mleczko is often used to refer similar candies with vanilla, cream, lemon or chocolate taste. The phrase Ptasie mleczko is a registered trademark in the EU, number 00334752291.