MIDAS Documentation v4.19
A "Tentative" booking is one which will be automatically removed from the scheduling calendar if it has not been "confirmed" within a certain time frame.
The Tentative Bookings feature may be enabled/disabled via MIDAS Admin Options → Manage MIDAS → Manage Booking Settings
When enabled, you can select which of your Booking Types should be designated as "tentative" booking types.
Tentative Bookings behave just the same as standard "confirmed" bookings for the duration of their life span. However, if a tentative booking has not been manually updated to become a confirmed booking (by modifying the booking and changing its Booking Type accordingly to a type with a confirmed status) within a definable time frame then MIDAS will automatically remove the tentative booking and free up the venue/time slot it previously occupied.
Tentative bookings are denoted by a icon on the booking within the booking grid.
For more information on configuring tentative booking types and their expirations, see: Manage Booking Types