First-class fliers have a code. It’s subtle and usually comes with a glass of champagne. If you want fit in before you fall flat in a sea of stares, learn the unspoken rules—lest you mistake the amuse ...

Looming on a screen above a room crammed full of top decision makers from rival airlines across the globe, Emirates President Tim Clark took aim and threw down the gauntlet. His target? The toilet. “I ...