PICC Removal

I have a question on PICC removal. I know after the MD removes it, the RN needs to measure it. However, I've heard you must measure the tip to the "hub." This confuses me. Some refer to the port (as in the plast piece on the end we clean and flush with the needless saline syringe) as the hub. And others refer to the point in which the lumen break off into double or triple lumens as the hub. Where am I measuring to!? Thanks!