A specific set of flights may be partitioned into fares and priceable units in many, many ways. For the four flights shown above 6 possibilities are shown (there are more). Each red line represents a fare component and each yellow polygon a priceable unit. For example, a round trip PU may be used with one fare paying for both outbound flights and one for both return flights. Alternatively two open jaw priceable units can be used, each containing two fares, each fare paying for one flight.