id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
23294	"Request for ""defer to existing"" tag merging feature in addition to the ""overwrite"" option"	VAis4mappers	Tyndare	"As I mentioned in the JOSM channel in the Discord chat, I was wondering if it would be possible to add a conflation feature in which certain reference tags would only be merged to subjects if the subject does not already have that key.

Currently, when merging two objects' tags with conflicting tags, the user has to manually resolve the tag conflict. The only way to avoid this is to put the tag in the ""Overwrite tags without confirmation"" box, and obviously this means the reference tag takes over whatever is on the subject. It would be immensely beneficial to add a feature that essentially does the opposite of the ""overwrite"" feature: enable users to indicate which tags should defer to the **existing** key-value pair when there's a conflict between the reference and subject.

Just to demonstrate:
||= Method =||= Reference =||= Subject =||= Result =||
|| (existing) plain || amenity=cafe || amenity=bar || Conflict (manual resolution) ||
|| (existing) overwrite: amenity || amenity=cafe || amenity=bar || amenity=cafe ||
|| (proposed) defer: amenity || amenity=cafe || amenity=bar || amenity=bar ||"	enhancement	new	normal		Plugin conflation