2005 America Vapor Recovery System

I'm doing some maintenance on my daughter's America. The vapor recovery system's lines and connectors were all split and disconnected. I have a diagram, but need some clarification with some of the symbols. There's 2 squares in the diagram with the numbers 1 and 2 in them. I assume the represent the two cylinders, 1 left, 2 right. The vapor line coming from Aux. canister appears to have a "T" fitting with one side plugged, or is it some kind of fitting? Any clarification would be appreciated.
Thanks