Boost control solenoid question (98 GTP)

The boost control solenoid has an electrical connector, a vacuum port to the bypass valve, and a vacuum port to the supercharger. There is a third port (with some type of retaining clip) that also looks like a vacuum connection. But nothing is connected. I can't find any reference to that port in the service manual. Should anything be connected? What is it?

it is a vent to atmosphere its supposed to be open/in tubed lol if that makes sense. made an account to write this 4 ya

Finally...I've been waiting so patiently for an answer. Thanks!