Is there some sort of unique "marker" that I can assign to all of the people in a file prior to merging so that I can use that "marker" to separate all of these people later for reports, exporting, etc? I currently have three files that I want to treat this way. One file is 100,000 people and the other two are about 2000 people each. I was hoping I could create a unique Fact label in each file prior to merging, but, I afraid that the combined file will assign the unique Fact labels to all people in the combined file.
I'll experiment with throw-away copies of the files and see what happens.