In the monthly view on the Outlook 2010 calendar, you have the option of several “Detail Views” – Low, Medium and High. If you accidentally select anything other than the default of high, you might be in for a surprise – with any other view most of your calendar items don’t appear.

• Show Low Detail – Only holidays appear on a blank calendar.
• Show Medium Detail – Holidays and color bars appear that indicate days on which you have calendar items.
• Show High Detail – Time and header information, including category colors for calendar items appear.

I’m not exactly sure when I’d have a use for any view other than high detail, but this is useful information in case appointments suddenly disappear for you or someone you support.