Source:Bing Meaning?

What does it mean when someone tags a way or node with ??

That the information is taken from bing aerial images.

Danke!!

Specifically it has to be taken from those aerial images that Bing permits OSM to use. These are ones take from directly above (give or take parallax) and with not anotation.

see http://wiki.openstreetmap.org/wiki/Bing for details!