What are Store Order Replenishment items in SIM?

 Hi I was going through the item request functionality and I am confused with the Store Order Replenishment item.

It says the time slot functionality is only for Store Order Replenishment item..................

What items are they? Can we generate purchase orders for them or how can we track that this item is Store Order Replenishment item or etc.

Is there any specific range of items which comes under this?

Please let me know if any one has any input about the description of these items with good example to learn..

Thanks in advance.

Thanks

Fahad