Under Custom Fields, an admin clicked Configure on a field. Click the delete (garbage can) on a context. There is no confirmation prompt. The field and all values are deleted from ALL issues for that project. There is no Undo button, no description in the Log file.
This just happened to us. The business is unhappy to loose all the data from project.

A prompt saying "Are you sure you want to delete this context? The action cannot be undone.'

Even better, a detailed record in the log file about what was done with a revert option.