1. The default fields Item ID, Item Name, Assignee, Estimation Points, and Timer cannot to removed from visibility.
   
2. The rest of the fields like Attachment, Checklist, Linked Items, Comments, and All tags can be hidden or shown based on your preference.

Customize field view

1. Click the gear icon in the top right corner. The settings window will appear.
   
2. Click on Backlog Customization under Personal Settings. The card customization window will appear.
   
3. Select the required project.
   
4. Go to Card.
   
5. Select the customizable fields that you want to include in the card view. For instance, if you want to include Comments field, select comments.
   
6. Click the Update button.
   
7. Navigate to the board to view the changes. The fields included are available when you click the ellipsis icon in the item card. 

Add fields to the view

1. Select the required project.
   
2. Go to Card.
   
3. Select the customizable fields that you want to include in the card.
   
4. Click the pin icon. For instance, if you want to pin Linked Items field, select the field and click the pin icon.
   
5. Click the Update button.
   
6. Navigate to the board to view the changes. The pinned fields appear as icons on the item card. In this case, Linked Items icon will appear on the card.