Note Flags are customizable reminders that get attached to your notes. If
you're in a meeting and you have been assigned a "to do" task during that
meeting, you can write a reminder in your notes, add a Note Flag, then use
the Notes Summary Task Pane to see all of these flags.
On my work Tablet, I have different flags in OneNote for work and personal
to-do's, for all of the people with whom I have regular meetings and for
phone calls I have to make. If I'm in a meeting with John, and I make a
note to myself that I have to ask Jane a question, I flag that note with
Jane's assigned flag, then when I meet with Jane later, I have the reminder
right there tied to her name that I need to ask her something. Do I have
five minutes in between meetings to make a call? Search for all notes with
the "Phone Call" flag attached to it. Need to send an email to my mom?
Write a note, flag it with the "Personal To Do" flag, then search for
anything with that flag when I get home.