i want to add an extra field to reviews that DOES NOT show up in the review itself
eg.  there is

Review Title (Shown)
Review Description (Shown)
Name (Shown)
Email (Not Shown)
Created (Not Shown)

i want an extra field
Date work done (Not Shown)

i can see how i can add an extra field with multiple fields but that would be visible in reviews ,.. and i want this for my reference not for public view