Coworker 1, his screen shared: types "the system's requirements"
Coworker 2: "Take out the apostrophy"
Me: "What? No, it's possessive"
Coworker 2: "The system is requirements? That is nonsense!"
Me: "It isn't a contraction. The apostrophy is being used to indicate possession"
Coworker 2: googles, is flabbergasted.