Image metadata properties are not validated for correct XML output.
As an example, the 'ALBUM ARTIST' property generate <comments ALBUM ARTIST="XX" /> which is not an attribute called ALBUM ARTIST, but an ARTIST attribute with another, ALBUM one without value (which is invalid).
Version: unspecified
Severity: enhancement
URL: http://commons.wikimedia.org/w/api.php?format=xml&action=query&prop=imageinfo&iiprop=metadata&titles=Image:Nl-Mexico.ogg