Is it Really So Hard to Communicate Clearly?

I can only imag­ine the con­ver­sa­tion around this web form:

 Devel­oper 1: “All fields are required.”

Devel­oper 2: “What if the user doesn’t live in the US, they won’t have a zip code.”

Devel­oper 1: “Then then can just leave it off.”

Devel­oper 2: “So… it’s optional?”