I ask because I just searched for my one town, and found two DAs, and... they're both definitely mine, but did the database just goof and leave two versions, or did someone somehow clone my town or something?
If I remember right,the Dream Suite sometimes saves earlier versions of your dream town.I recently visited one of my dream towns and there was two versions listed,the current version and a previous version.I visited both and they had different dream addresses and different dates(that information is on the dream town's bulletin board),so it probably has something to do with the dream address changing.I think the previous versions eventually get removed.
My main town has 2. Awhile back I imported my 2013 main town cartridge to a NEW Welcome Amiibo Cartridge.
It got a new dream address when I updated the dream suite. More people visit my old dream address and I don't have it listed anywhere.
If you play on a different 3DS and update the dream suite the address will change. I did that with a couple of towns. Those have 2 DA.