Navigate to the Metadata tab on the Modify Question page while modifying an item.
Click the Show Enemies button to load the list of existing enemy items (if any).
Clicking the Show Enemies button also reveals the interface to add new enemy items.
Enter the Question ID or at least three characters from the stem text of the item to be added as the enemy, in the Add new enemy text box.
A drop-down appears below the text box with information about an existing item in the form of “Number: Question ID Text: Stem text”. Click on this drop-down to select the item to be added as an enemy.
The selected enemy item details are now visible below the Add new text box. Click the Add button to add the selected item as an enemy.
The enemy item details now appear above the Add new enemy text box, in the list of Enemies. You can add more enemy items in a similar way and they all appear in the list of enemies.