If an approved CRS, for which a ticket has been purchased, does not fit in a particular seat on the aircraft, the aircraft operator has the responsibility to accommodate the CRS in another seat in the same class of service. (havebabywilltravel.com)
For instance, if you took an award flight to Hawaii in July, 2017, use Expedia or your favorite travel booking site to look up the price of flights in that same class of service in July, 2018. (wisebread.com)
Both passengers must be booked at the same time, in the same class of service and in the same record. (americanexpress.com)