Ok RVR reminded me of something. I have heard of Capt. that write down their FO's name and FO's that write down the name of their Capt.'s in their logbook. What purpose does this serve? What do I care a month or so down the road that I flew with XXX on flight XXX from XXX to XXX? I don't get it, someone please enlighten me. It's not worth the ink in my pen in my mind.