I had created a personal tag for use on my cards and subsequently decided I did not want to use it, so went to remove it.
I removed the tag by going to Your Collection - Reports - Collection Tags
From there I pressed the edit button next to the tag, I pressed the Delete button and was presented with a warning/message reading as follows 'Are you sure you want to delete this tag and remove it from all cards?'
I did wish to do so, and selected Yes.
Outcome:
- the tag is no longer there in the reports-collection tags list
- the tag is no longer available for selection when adding personal tags to a card
- however, unlike what is suggested in the messge, the tag was not removed from the cards it was assigned to, every card where I had put it in still has that tag.This was done 24+ hours ago, so I don't think it is a database refresh or similar. And now I'm having to go and manually remove from every card when I see it.