> "If it connects, it should work" used to be largely true Gods no! There are innumerable devices with D-sub, mini-DIN, RJ-11, RCA, or TRS connectors, that put

> "If it connects, it should work" used to be largely true Gods no! There are innumerable devices with D-sub, mini-DIN, RJ-11, RCA, or TRS connectors, that put those connectors to entirely different and incompatible purposes. With entirely-incompatible electrical standards, even, such that plugging client-devices intended for one purpose into host-devices intended for a different purpose will electrically short one or both. Remember the iPod Shuffle's "USB-A to TRRS" cable? Guess what happens when you try to use that cable to, say, plug your computer into your hi-fi? Or — less absurdly — into your TI-84 calculator? The "Universal" in USB is in contrast to the DB-9 serial port, which was decidedly not universal. Yes, there were actual "serial ports" and "serial port devices" — the spec is called EIA/TIA 232, if you're curious — but there were tons of other things that used DB-9 connectors (male or female) but weren't EIA/TIA 232 devices. Plug one of those into a serial port, and poof! — there goes the magic smoke. You don't have to worry about that with USB (including USB-C); USB ports and cables all follow a single unified electrical pin-out specification, whatever they're carrying. Even USB-C devices that mis-implement features like USB-PD (e.g. the Nintendo Switch) won't ever start an electrical fire, because — whatever logic-level protocol support they might have mis-implemented — they're still "USB-standard devices" on the electrical-pinout level. Now, these are all fairly-old connectors I'm mentioning, so you'd think we'd have learned better by now; but special mention goes to the Atari joystick port (technically a type of D-sub connector), which is still to this day slapped onto arbitrary generic Shenzhen-special "TV plug-and-play consoles" — with no two devices being wired the same way, and so only actually supporting the gamepads the console comes with. When you think about it, relative to this disaster, USB-C does guarantee you that 1. plugging any two USB-C ports together with a USB-C cable won't throw your circuit breaker; and 2. as long as both devices are data devices, you'll get at least USB2 data-transfer out of the arrangement (if you're plugging in a legacy USB2 device), and much more likely USB3 speeds. Everything is actually compatible with everything, as long as you don't care about getting the fastest line-rates possible.