Archive (tag)
From SnapMap
archive=<archive name> specifies the archive in which the image resides. It should be human-readable. It is recommended that it is wrapped in <a href="..."></a> tags so we get the archive's website (the home page) from the same tag. The home page may also be helpful for merging similar names.
Example
archive=<a href="http://www.nationalgallery.org.uk/">The National Gallery</a>
Note
It may turn out that it's better to separate website and name into two tags, archive and archive_website.
