I'm confused why it shows detail like holding position markings, but not taxiways or hot spots. And it conflates locations using different hold short markings (ILS and runway).
In Frankfurt at least I see the ILS critical areas tagged with "holding_position:type: ILS". For instance south of arrival end 25C. Looking at aerial imagery these do correctly align with the ILS and hold-short markings.
Edit: it does appear that hold lines are mis-tagged in some spots, e.g. north of arrival end 25C.
It's just showing OpenStreetMap data. Anyone can edit and add data. The data that's in there is just what enthusiasts have added in the past 20 years. If no one added it, it's not there. You can add data if you like.
