Clarification on 3 cent nickel proof variety registry set

Wxcloud1

Looking for some help on clarification of this registry set. Specifically the 1887/6 varieties listed in order to complete the set. Its my understanding that all proof coins this year, have the overdate and the overdate is either a strong or weak. However, The PCGS registry set show 3 coins for this year 1887/6, 1887/6 weak, 1887/6 strong. Am I correct in assuming that the 1887/6 graded coins are in reality either a weak or strong variety, they simply just don't have the attribute added to the label? Also is the 1887/6 really a variety of this set or is it just a coin that was graded without the attribute? Any help is appreciated. Thanks

ms70

You will probably get a faster answer from people who know if you post this in the U.S. Coin Forum.

Though it's a registry question, just rephrase it to be about the coin and not the registry.