Retroactive Pricing for Standard PO

Dears,

I want to use Retroactive Pricing feature for Standard PO not for Agreements.

But I found the following profile option specified for releases ;

PO: Allow Retroactive Pricing of POs

The profile can be set to the following options:

1. ALL RELEASES

2. NEVER (or not set)

3. OPEN RELEASES

And the following concurrent "Retroactive Price Update of Purchasing Documents Program" has parameter Agreement Number so PO number not in this parameter LOV.

So, How to use Retroactive Pricing feature for Standard PO?

thanks.