Item Class Serial/Lot Mask supports defining a single serial or lot number mask which applies to all serial or lot numbers generated for the items with an Item Class. Each serial number generated will be unique for the entire class of items. One item in the Item Class is selected as the Master Item. Its Serial/Lot Number Mask is used as the Mask for all Serial/Lot Numbered Items in the Class. An Item Class can have either Class-level serial numbering, or lot numbering, but not both.