Edit: Nuts! I just re-read your question and realized you were talking about the appointments section, not the tasks section. I don't think there's a way to hide specific appointments in that section. You can hide all of the appointments by right-clicking on "To Do Bar" and unticking "Appointments", but I can't see a way you can filter them.
You can set up a filter on the tasks to hide certain messages/tasks:
- Right-click the task area and select "Filter..."
- Click the "Advanced" tab
- In the "Define more criteria" area:
- Choose a field (if these meetings all have the name/subject of "Scrum", choose "Subject")
- Change the condition to "doesn't contain"
- In "Value", put the text of the subject you want ignored (for example, "Scrum")
- Click OK
You can set up all kinds of filters on the tasks area - the only other example I could find was at the How-To Geek for only showing today's tasks.
By default, Outlook has 2 filters already in place it uses to only show incomplete tasks:
- Date Completed (does not exist)
- Flag Completed Date (does not exist)