I want to delete tags for some of my early forums and exchange modules which have lots of tags users created.   It wont allow me since they are in use I get an error.  So my work around would be to edit these tags from these topics manually then delete attempt to delete the tag I wish to remove.

A way to speed up this process is to allow me to merge all topics that have the tag I wish to delete and move to an existing tag to ensure the discussion gets a tag and avoid other potential errors of posts not having a tag due to being deleted which is why I believe this warning is popping up.

My idea for a solution is to allow tags to migrate or merge two or possibly more tags together.   Lets say I want to move 10 tags to a "general" tag as generic as it can be to move off topic things over or I wish to reconfigure my tag system.  A way to take a tag and combine it to another one should be fairly straight forward logic.  And if you merge them to another tag the system would essentially be renaming the tags for the discussion to add the tag it is being merged to unless that tag is already set on that topic.  In the end you will no longer have the old tag.