For sending the contents of one in-stock request by multiple boxes, stick on the in-stock label and include the in-stock detailed statement in each box.   
In that case, to help us recognize the item and its quantity in each box, Please circle the item in the applicable box and leave a note of the quantity on the detailed statement.

In the event that the boxes arrive on different day, as the earlier arrival box will have the in-stock request which completed the operation, the later arrival box can be registered as Unknown box. Therefore in that case the unknown box must have new in-stock request to link with the box arrived earlier.

For registration of unknown box, see ‘How can I handle my pending stock?’