My source added: "It's in the PCIe 5.0 CEM spec. Not sure how many people got it wrong and why it's suddenly "news" because of ASUS. The 12-pin portion is actually the same as the FE connector". "And ...
ASUS China is giving away some 16-pin PCIe 5.0 power cables for its enthusiast-grade ROG Thor PSU family. If you don't have or won't be buying NVIDIA's new flagship GeForce RTX 3090 Ti graphics card, ...
I think I've seen both eg the more typical 5 pin on most Cameras MP3 players etc and then the 4 pin that comes on the Pentax Optio S4 for example.