catalog_id (tag)
From SnapMap
catalog_id is the main way to specify the ID used by an archive, museum or other institution for the image in question. It often relates to a physical object: a painting, a negative, a book, or a photographic print for example.
Example
title=An Old Peasant caresses a Kitchen Maid in a Stable type=painting artist=David Teniers the Younger thumbnail=http://nationalgallery.org.uk/upload/img_100/N-0862-00-000023-WZ.jpg src=http://nationalgallery.org.uk/upload/img/teniers-old-peasant-caresses-kitchen-maid-stable-NG862-fm.jpg date=c1650 dimensions=43.2x64.9cm catalog_id=NG862 archive=National Gallery, London
