@bclerdx #3 USB-IF 官网有 PDF 免费公开（《 Universal Serial Bus Type-C Cable and Connector Specification
》）
https://www.usb.org/sites/default/files/USB%20Type-C%20Spec%20R2.0%20-%20August%202019.pdf

2.2 USB Type-C Receptacles, Plugs and Cables
The following USB Type-C receptacles and plugs are defined.
• USB Full-Featured Type-C receptacle for USB 2.0, USB 3.2, USB4 and full-featured platforms and devices
• USB 2.0 Type-C receptacle for USB 2.0 platforms and devices
• USB Full-Featured Type-C plug
• USB 2.0 Type-C plug
• USB Type-C Power-Only plug
The following USB Type-C cables are defined.
• USB Full-Featured Type-C cable with a USB Full-Featured Type-C plug at both ends
for USB 3.2, USB4 and full-featured applications
• USB 2.0 Type-C cable with a USB 2.0 Type-C plug at both ends for USB 2.0
applications
• Captive cable with either a USB Full-Featured Type-C plug or USB 2.0 Type-C plug at one end
• Active cables as defined in Chapter 6

有「 USB Type-C Power-Only plug 」，但是没有「 USB Type-C Power-Only cable 」，USB Type-C cables 的最低定义是 USB 2.0 Type-C cable 。


2.3.2 Plug Orientation/Cable Twist Detection
The USB Type-C plug can be inserted into a receptacle in either one of two orientations, therefore the CC pins enable a method for detecting plug orientation in order to determine the lane ordering of the SuperSpeed USB data signal pairs functionally connected through the cable and identify the Configuration Lane for dual-lane operation when supported. This allows for signal routing, if needed, within a host or device to be established for a successful connection.

是强制的。