Compare http://musicbrainz.org/ws/2/label/89a9993d-1dad-4445-a3d7-1d8df04f7e7b and http://musicbrainz.org/ws/1/label/89a9993d-1dad-4445-a3d7-1d8df04f7e7b.

According to http://svn.musicbrainz.org/mmd-schema/trunk/schema/musicbrainz_mmd-2.0.rng there should be a disambiguation element in the label element.