Automatic contract determination while Sales Order creation

Hi friends,

Our SAP system receives Inbound Sales Orders in which there is no reference to Contract. All the sales orders items should have reference to a contract.

When I enter Material no and req. date at item level, I get the following info message

V1 728 - Material &1 has exactly one outline agreement/contract: &2

Somewhere it is determining the possible contracts for that combination. But I am not aware where does this setting is done in SPRO.

Please let me know the config steps if anybody knows.

Thanks in advance.

AK