Showing, hiding and highlighting tasks
Not every task needs to be tracked in the markbook so there are options to hide ones that are not needed and highlight ones that you want to be able to quickly draw your attention to.
The highlighted task is shown with the yellow highlights. This is especially useful if there are certain pieces of work that are part of assessed work etc.
Selecting Highlight and Un-highlight toggles whether the task is highlighted or not.
Perhaps you have a task which was a simple reminder for the class or a form rather than a piece of assessed work, then selecting Hide will remove it from the markbook. A reminder that you can unhide the task will show.
For any task, you can select Markbook Status and choose whether to show that task in the markbook.