From The Food Encyclopedia by Jacques Rolland and Carol Sherman
A long, yeast roll split down one side (almost, but not quite all the way through), used to sandwich a hot dog. A New England hot dog bun is cooked in a special individual pan, so that it is rectangular and has no crust on the sides, which allows it to be toasted on both sides until crisp. The bun comes pre-split down the center of the top and condiments are drizzled down the center of the hot dog after it's placed in the bun. These buns are also the essential basis of other popular New England sandwiches, such as the clam roll (a bun filled with fried clams) and the lobster roll (a bun filled with lobster salad).
