Also known as Soft MLOS or Flexible MLOS.
A reservation needs to have a certain number of nights if the date is part of the reservation.
For example, you put a Soft-close for 4 nights on 01/05. Any reservation going through 01/05 will have to have 4 nights. Whether it is 01/04 to 01/08 (4 nights) or 01/02 to 01/06 (4 nights) or 01/05 to 01/09 (4 nights).