Registry question from the new guy
This is my first time wandering over to this side of CU. I recognize a lot of guys from the regular sports card forum. So, I have started collecting a handful of modern players. One of them doesn't even have a registry set yet, at least that I can find (Anthony Davis--the basketball player) and the other (Andrew Luck) has a registry set for his RC's but I have a number of cards that are RC's but are not listed in the set. So my question: how do you get cards to be added to an existing set (if you can)? And, how do you start a registry set if you need to? Thanks in advance for any help.