Specific terms and conditions for a selected rate can be configured via the Rate Policies.
Click on the link Rate Policies under section Rates:
Click on the blue Add button:
Type in a name for the policy: this can be the same as the name of the rate linked to it. Also type in the policy content in the second box:
Activate the policy by checking the Status box and select the rates where the policy should apply. When finished, click on the button Save: