Minimum Release for a contract purchase agreement ?

 Hi,

I have a question : In the Oracle Purchasing User’s Guide (Purchase Orders 4 - 75), I found this text :

" 4. For planned purchase orders, blanket purchase agreements, and contract purchase agreements, enter the Amount Limit (for the
total of all releases) and the Minimum Release Amount that can be released against this purchase order. For blanket and contract
purchase agreements, the Amount Limit must be equal to or greater than the Amount Agreed. Enter Effective from and to dates
to limit the agreement controls by time."

I'm referring to the Terms and Conditions form using this navigation:

1.  Navigate to Purchase Orders / Purchase Orders using the Purchasing responsibility.