Please clarify where you saw and USB E34 :
The "E" in these labels typically refers to or Embedded headers on your motherboard, and the numbers "12" and "34" correspond to the specific pair of USB ports they support. usb e12 vs usb e34
used by motherboard manufacturers to identify physical connection points for your case’s front-panel ports. The Core Difference: Internal Routing Please clarify where you saw and USB E34