If you have put an email or comments in the meeting date I always recommend typing (SEE BELOW) or (OPEN TO READ COMMENTS) in either the Subject or Location box. If they are not in the habit of opening the meeting date they may not realize it is in there.
Other things you can put in the comments section would be:
- call-in numbers if it is a teleconference
- address/directions to get to the meeting
- confirmed attendance list with phone numbers (especially if your boss is the Chair)
- and any other information you think would be helpful