If the box is not checked, the system does not take into account the FIFO date of the location. This value is selected by default in the case of a "Picking" type location. In effect, a location can accommodate different FIFO dates (depending on the replenishments, for instance) at any given moment. In that case, each object put on this location keeps its own FIFO date.
If the box is checked, the system takes into account the FIFO date of the location (instead of the FIFO date of the stock object) in the output search algorithm. The FIFO date of the location is equal to the date of the first object put in this location. All the stock objects then take the the FIFO date of the location.