This is the Type-I or Early obverse design for the 1944S 50 Centavos, one of a number of new Allen Varieties to be added in the 8th Edition. It has not been assigned an Allen number yet, but will most likely be Allen-15.01b.
These coins are easily distinguished from the much more common Type-II variety by the shape and style of Mt. Mayon on the obverse. It took several years and multiple conversations with NGC, but they now officially recognize this variety as part of their Variety Plus Program.
Click on the image to view the NGC Variety Plus page.