A change whose amounts are not all in one currency is rejected unpriced.

A type code names a collection exactly when an amount is due to the airline.

A type code names a refund or a value store exactly when an amount is due by the airline.

When the seller asks to keep the value of cancelled items for later use, the differential is typed Reusable and both due amounts are zero.

For every change or cancellation the airline prices, the amount due to the airline less the amount due by the airline is the new price, less the old price, plus the penalty, plus the forfeited amount.

Open question for the business. Two cases break it. When the seller asks to keep the value of cancelled items for later use, the guide shows both due amounts as zero, while the formula gives the whole refundable value as due by the airline; the example respendCancellation shows it. Under the reading that waives a penalty above the refundable value, the airline charges less than the penalty, so the formula overstates what the customer pays; the example penaltyAboveRefund shows it. Should the value held for later use count as the new price, and is a penalty above the refundable value collected or waived?

Given a change priced in euros whose penalty is stated in US dollars. The guide's sample change record shows a similar mismatch between the currency of its prices and that of its due amount.

When the airline prices the change.

Then the change is rejected unpriced.

Given a paid trip at 1,000.00 EUR, of which 120.00 EUR is forfeited, changed to a trip at 900.00 EUR with a penalty of 40.00 EUR netted. These are the figures of worked example EXM_ORD_003C.

When the airline prices the change.

Then the customer pays 60.00 EUR, the airline returns nothing, and the type code is AddCol, as in the worked example.

Given a paid trip at 1,000.00 EUR changed to a trip at 840.00 EUR with a penalty of 60.00 EUR, where the airline keeps what it owes in a value store. The amounts due match worked example EXM_ORD_003G.

When the airline prices the change with the penalty netted, and again with the penalty charged separately.

Then netted, the customer pays nothing and 100.00 EUR goes to a value store. Charged separately, the customer pays 60.00 EUR and 160.00 EUR goes to a value store. Either way the customer is 100.00 EUR better off.

Given a paid order at 1,000.00 EUR, of which 20.00 EUR is forfeited, cancelled with a penalty of 50.00 EUR netted and a refund. These are the figures of worked example EXM_ORD_030B.

When the airline prices the cancellation.

Then the airline refunds 930.00 EUR and the type code is Refund, as in the worked example.

Given a paid order at 1,000.00 EUR, cancelled with no penalty and no forfeit, where the seller asks to keep the value for later use. This is worked example EXM_ORD_030E.

When the airline prices the cancellation.

Then the differential is typed Reusable with both due amounts zero, as in the worked example. The formula of ONE-201.5 requires 1,000.00 EUR due by the airline.

Given the cancellation of worked example EXM_ORD_030B (a paid order at 1,000.00 EUR with 20.00 EUR forfeited) with a penalty of 1,000.00 EUR netted in place of 50.00 EUR. The refundable value is 980.00 EUR, less than the penalty.

When the airline prices the cancellation under each reading of the guide.

Then under the reading that collects the whole penalty, the customer owes 20.00 EUR on a cancellation. Under the reading that waives the excess, nothing is due either way, while the formula of ONE-201.5 requires 20.00 EUR due to the airline.