You use the Reservation window to make manual reservations.
The tabs display information about the item for which a reservation is required. Each line in the window displays information about one type of line (sales, purchase, journal) or entry. The lines describe how many items are available to be reserved from each type of line or entry.
If you are reserving specific item tracking numbers, and some or all of those item tracking numbers already have non-specific reservations, the window shows a message at the bottom that tells what quantity of the item is already reserved on a non-specific basis. You can still place a specific reservation on these item tracking numbers if sufficient unreserved inventory exists.