Bonnet, one of the least common roofs, could be considered a modified hip roof style. Usually found in French Vernacular architecture bonnet roofs have two slopes on all four sides of a structure. It is essentially the opposite a mansard roof in that its upper slope is steeper than the bottom slope. The bottom slope often hangs over the house to cover an open sided porch and provide shelter from the sun or rain.
Bonnet roofs are sometimes referred to as "kicked eaves" roof. Kicked eaves are considered a "roof enhancement" creating a visor effect to the house.