Lower level of priority to be fully curtailed before higher level; partial curtailments.

1. Before a utility may curtail in full its supply of natural gas to a customer who is entitled to a particular level of priority, the utility must curtail in full its supply to all its customers in lower levels of priority. 2. Any partial curtailment of supply within a priority must be made in proportion to the stated daily requirements for natural gas of each customer entitled to that priority.