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If a column is being used by one or more boards at the moment of the exclusion, you will be prevented from deleting if it unless you’re the column owner or the admin for all boards that have that column.
An admin for all boards can always delete a column straight way. Other users may need to individually remove the column from each board to be able to delete it.
After deleting a column, it will no longer be available for adding to a board. If you wish to revert this action, you’ll have to create the column again.
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