In tag merging process (available for moderators) when the resulting tag name doesn't exist yet the process will behave like a tag renaming. I.e. all tag info (short and detailed) will be "moved" from the source tag to the newly created tag.
I think it would be very useful to move tag info even in situation when the target tag exists, but doesn't have info at all.
In general, the tag merging process should also takes into account info from the both (source and target) tags to create some combined (manually or automatically) info in result. This will reduce (or even make it not needed) the time to retrieve info from orphaned tag.
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