What is the dress code at United States Postal Service?

Long- or short-sleeve, dress-style woven, solid postal blue or postal blue with red and blue pinstripes and vertical corporate emblem

Trousers walking shorts in postal blue with braid stripe

Socks that are calf-length, crew style, or quarter-length uniform blue-gray, black, or white with blue stripes.

Shoes are black leather with a visible SR/USA label.

Headgear: Service cap, postal navy blue; baseball cap, summer or winter style, postal blue with the vertical corporate emblem; sun visor, postal blue with the vertical corporate emblem