While deleting a trader you can come across different options.

-Just delete it

-Delete and add to blacklist, so that the trader couldn’t be registered once again. Usually the reason of adding the trader to blacklist is mentioned.

-Delete and add to the global SmartCJ base. We have this base on our server and if someone adds a trader in this base, every user of SmartCJ can see it in his admin area when pointing at this trader with a mouse. Take a look at SmartCJ Global BlackList

-Delete to trash . The trader is just deleted from the main list, trade with it stops, but you can easily restore it (menu Trade→Trash)