Hi,

Most of these seem to be houses that were started in the 2000-2010 period and never finished. Sometimes it is a whole street of houses. https://en.wikipedia.org/wiki/Ghost_estate

The tag doesn't seem to have been applied to ruined / demolished buildings.

I found some others just now and the buildings were finished or a different building built at the same location.

Review and re-tag seems to be the way forward.  66 of 78 instances worldwide appear to be in Ireland or Northern Ireland.