I have two spatially identical points that represent two apartments in one building under one address. I only need to label the address, not the apartment number, and the client does not want me to merge the points into one. So, I'm now left with two identical labels for one building. Is there an easy way to remove duplicate labels that exist between two separate features? I just need to show the address once.
You need to use Maplex labeling. The Remove Duplicate option in Label Density works there. In the linked example, they were not using Maplex. Set the distance to a big distance because it sounds like you'll never want to label the same address twice.