This is where most people accidentally start a small war at the village fête. The Union Flag is not symmetrical. Repeat after me: not symmetrical. The white diagonal stripes are arranged with one “broader” side and one “narrower” side. The broader white stripe must be on top on the side nearest the flagpole. Always. It’s the rule.
If you hold it up and the broader white stripe is on the bottom, well done—you’ve just flown the flag upside down. The upside-down Union Flag is technically a signal of distress. And while your washing line might feel distressed, your neighbours will just think you need glasses. So check it. Hang it so the thicker white stripes are in the top left corner as you look at it from the ground.
A good trick: imagine the flag has a little drunken stagger. The broader white stripe always leans left like it’s trying to get home after a long pub session. Never let it lean right. That’s the when-everything-is-terribly-wrong lean.