This field displays the lowest installed internal code change level that can be removed such that the remaining installed change level can be activated concurrently. That is, you can remove all change levels installed for an object, from the current installed level down to and including the removable concurrent level, and then activate the change level that remains installed without disrupting the operations of the system.
Compare the number in this field with the number displayed for the installed level to determine whether one or more change levels currently installed can be removed concurrently: