Workflow action on completion

In the template there is the section  "Workflow Action" . 
 
 Run action on completion  enable. 
 Action on Completion  choose (depending on the primary table):
 
 Release / Reopen (only for certain document tables) 
 Custom action (codeunit/report) 
 Define field value assignments 
 
 
 
 When  Define field value assignments  is selected, the section appears  Field Value Assignments .