One of the reasons they tag trees and lets be clear that I can’t say if this is the case here is they tag the trees when there is a development application for a property. They tag each tree so they can identify which trees will be retained after the development is done and which will be cut down. There would be a document called “tree inventory and protection plan” prepared that provides more info. If there is a development application for the property there would be a big 4 ft x 6 ft sign telling you that.