The Yin Linking Vessel, Yinwei Mai, performs for the body's yin channels the same binding function the Yang Linking Vessel performs for the yang ones, running along the inner aspect of the limbs and trunk and drawing the yin channels' separate territories into a single coordinated path. Its route places it deeper in the body's functional geography than its yang counterpart, consistent with the general Chinese medical association of yin with interior rather than surface processes.
That interior orientation is reflected directly in the symptom patterns classical sources attribute to its disorder: rather than the exterior chills and fever tied to the Yang Linking Vessel, disturbances of the Yin Linking Vessel are associated with interior conditions, in particular pain located around the heart and chest, symptoms read as arising from within the body's depth rather than from an external attack still at its surface.
Its confluent point is Pericardium 6 on the inner forearm, paired with Spleen 4 on the foot, and the choice is telling: Pericardium 6 is among the most used points in the whole of acupuncture for chest oppression, nausea and palpitation, which is precisely the symptom territory the classics assign to this vessel. The point and the vessel say the same thing.
Classical description places the vessel's origin at Kidney 9 on the inner lower leg and carries it up the medial aspect of the body to meet the Conception Vessel at the throat, so that the vessel binding the yin channels ends on the great yin channel of the front, mirroring its yang counterpart's meeting with the Governing Vessel at the nape.