Value for the type field in the appointment table.
0: Unknown - used when initializing
1: Show in diary. If overdue or done today, show in checklist also.
2: Appointment is a followup with no specific start time.
3: Paperclip on diary, expands to post-it note when clicked.
4: Document of any kind, including outgoing, incoming, and email.
5: Saved Report (not a Report Definition but the result of an actual report run).
6: Booking, made for diary. When accepted this will change type to inDiary.
7: Booking, made for check list. When accepted this will change type to inChecklist.
8: Document is a template for mail-merge operations.
9: Document is a result of a mail-merge operations (there are probably many documents like this!).