If you've built out a Subject that you'd like to be reference material, simply turn off completion tracking for the content by making it a Reference Subject.
To change a Subject to a Reference Subject:
Navigate to your Subject by clicking on the page where your Subject lives on the left-hand navigation bar (Company, Policies, or Processes)
Click your preferred Subject
Click on the three dots on the far right-hand side of the Subject title
Click "Advanced Settings"
Scroll down to the Advanced Settings portion of the Edit Subject popup
Toggle the "Require completion of Subject?" toggle off
Learn more about Reference Subjects.