Line items are entered automatically from the pick lines. The presumption is that if an item is picked, then it is shipped. As such, ship line items cannot be edited or deleted. Nor can you add a new line item.
SKU - The Stock Keeping Unit identifier for an item.
Item - The name of the item.
Shipped - The quantity and unit of measure of the SKU that was shipped. Note that this number may be different the quantity that was ordered.
Serials/Lots - If the SKU is serialized or has a lot number, that info is included here. For example:
Shipping Lines with an item with serial numbers