Thank you for looking into this. I am sorry if my picture was confusing.
Actually, I removed some options (Descriptions, Changelog, Author Name, Meta-Tags) from the search page. Moreover, the fields "About the Book" & "More details on the Book", which you see in the picture, are custom fields (and NOT new names for existing fields.)
What I was trying to demonstrate in the picture is that custom large text fields are added correctly to the list of options to choose from on the Search page. Examples of the custom large text fields are "About the Book" & "More details on the Book."
However, custom short text fields are NOT added to the list! I defined 2 custom short text fields. They display correctly on the details page and on the upload page. However, they do NOT display on the search page.