What is the contact for?

Question

Iron

Contact IntA_P2_D+ is responsible for this.

Answer 1

I think this document from Intel will help you Specification 3.0

Answer 2

Do you want to clarify what kind of connector, where it comes from, and so on?

Answer 3

Judging by the USB tag and the characteristic name of the contact, the USB3.0 block on the motherboard.
Then this is the D+ pin of the original USB 2.0, i.e. data transfer. USB3.0 mode without this pin will most likely not work either. But power is supplied to the port.