It can be described by clicking the "Page Settings (Scan Target, Memo)" button on each page from the screen transition diagram. When a memo is saved, a "☆" mark will appear on the page. Any color can be set.
It can be set in the following two ways.
Go to Scan Detail or Scan List > Hamburger Menu > Screen Transition Diagram.
Scan Detail or Scan List > Hamburger Menu > Crawl Results.