Sifting through the code it appears that a lock is placed on an
Item/Warehouse combination once a counting journal entry is created for that
particular Item/Warehouse. I have also proved this by creating a counting
journal entry and examining the InventItemLocation table.

So why the "Lock items during count" setting in Inventory Management =>
Setup => Parameters?

Is there a URL someone could share that provides a good explanation of this
setting and the typical environments where it may be used?