When it is canceld, it is deleted. You can't register it. But there is a history that is keept for a while and I can recreate that exchange. If you can't register an ID, you can write in the discussions, in the thread "Missing or wrong IDs"
Those situations are now exceptions. I had only a few cases.
If this situation continues, I will find a way to automate the recreation of those exchanges from a canceled history when that ID will be used.
Note that if that postcard is marked as "Mailed", it will not be canceled. It will remain there as expired and those can be registered and after 500 days.
Only postcards that have been sent 6 month ago and that have not yet reached its destination and also has not been marked "Mailed" by the sender will be canceled.
