Header (separator)

Header (also known as separator) allows to visually split checklist into parts or groups as presented on the screenshot below:

Add header/separator with a button

When adding new item or editing existing item there is an option so save text as a separator with the button:

 

Add header/separator without a button

When adding new item, editing existing item, using Editor or Checklist Text custom field, there is an option to add a separator by preceding the text with three dashes "---":