Accrue Expense Item at Receipt/Period End

Hi All,

I have just go through the Inventory Set up Purchasing Parameters and found the option Accrue expense at Receipt/ Period End appreciate if any one explain what is this, Further i have created a receipt with Option at Period End and there is no accounting even nothing found in  material transaction and in receiving Transaction Summary,if i change the option to at receipt level then no difference at all for this receipt and in case of matching Accounting Will be out,Appreciate if some one please guide me how to recognize that.