To designate certain tags that cannot exist at the same time, create one or more groups of exclusive tags:
This means that these tags can only exist one at a time for any pool member. So let's say you create a group of two tags that you use to track current city of residence, and you want to make sure that nobody can live in both cities at the same time:
Now moving forward, any time you go to add the tag Los Angeles to someone with the tag Minsk, it will remove the Minsk tag. That's because they cannot live in both Minsk and Los Angeles.
Why have tags in order in these groups? Priority logic.
You might be wondering why you need to drag tags in order within these groups. That's because time is usually the main driver, but when tags are added at exact same time, then priority comes in and decides which tag wins. See this example when you could add both tags at the exact same time:
Now Ethnio robots go back to the order of your tags and know that Minsk wins, so only that tag will be added, not Los Angeles.