From http://butterick.mccall.com/:
"MISSES' DRESS AND BELT: Mid-calf dresses A, B, C have close-fitting, self-lined bodice with side front and back seams, flared skirt with side pockets, back pleats and zipper. A: below-elbow sleeves. A, B: bodice back extends into tie ends. B, C: short sleeves. C: bodice back extends into band with button and buttonhole. Purchased petticoat.
Circa 1956."