We need to deprecate the publication <-> edition relationship now that there's support in the schema for setting the publication in edition data. This needs some interface changes to hide the deprecated relationship types in the relationship editor when creating new relationships. It will also be necessary to update the web service to send the deprecated status of the relationship type.

See:
http://chatlogs.musicbrainz.org/bookbrainz-devel/2015/2015-05/2015-05-15.html#T22-26-20-508601