"In addition to a master baseline, a further 10 baselines can be set. These can used in what-if? scenarios and as useful schedule comparisons. As an addition, current start and finish dates for all tasks or just those selected can be copied to interim values (Start1/Finish1). Both of these options can be accessed within the Save Baseline dialog box (Tools..Tracking..Save Baseline). Interim baseline information can be displayed on charts using a variety of bar styles.
SOURCE; microsoft project glossary-projectlearning.net"