Look on the back of your laptop charger and you’ll find a mess of symbols and numbers. We’d bet you’ve looked at them before and gleaned little or no understanding from what they’re telling you. These symbols are as complicated as the label on the tag of your shirt that have never taught you anything about doing laundry. They’re the marks of standardization and bureaucracy, and dozens of countries basking in the glow of money made from issuing certificates. The switching power supply is the foundation of many household electronics — obviously not just laptops — and thus they’re a necessity worldwide. If you can make a power supply that’s certified in most countries, your market is enormous and you only have to make a single device, possibly with an interchangeable AC cord for different plug types. And of course, symbols that have meaning in just about any jurisdiction. In short, these symbols tell you everything important about your power supply. Here’s what they mean. How did every power supply end up plastered with hieroglyphics? It works like this; Acme Corp wants to sell a Thingamajig in Benchoffistan, so the company sends a pallet of Thingamajigs there. The Customs officer ...