The USB-C connector is gaining in popularity, but it is also increasingly difficult to figure out what a particular instance does. To solve this problem, I suggest a simple system: colour codes that indicate the nature of a particular port. Ports that support multiple protocols can have a multicoloured hatchings. In the highly improbable that a manufacturer ads some feature to an existing port – say with a firmware update – this can be fixed with some sticker.

Here are some proposed values, largely based on the PC System Design Guide.

Color Codes for USB-C connectors

Legacy USB / Charging	USB 3.0
Power Delivery Specification	Display Port Alternate Mode
Thunderbolt Alternate Mode	HDMI Alternate Mode
Audio Accessory Mode	Maintenance / Firmware update only
USB Attached SCSI	MIDI
Serial Port Emulation	Parallel Port Emulation
Mouse	Keyboard

The fact you cannot tell immediately which ones are serious and which ones are not, is part of the problem…