Thanks for your response. I'm familiar with the check_date tag, I just haven't seen it being used in such a way (adding an older date). Are you using this for BTCMap in some way? I'm curious how you determine whether the user actually surveyed its existence or not? For example, on this POI https://osm.org/node/7056211216 , check_date was set to 2023-03-17, and the changeset from that date was someone doing tag cleanup with Osmose - almost certainly not a survey.