Most airline systems require a surname and given name/(s) be provided in the Passenger Name Record (PNR) and in the document fields for entering passport information. Challenges occur when the passport is issued with the surname or the given names field left blank. Depending on the airlines policy the agent will need to manually type in the blank field and may use the codes First Name Unknown (FNU), Last Name Unknown (LNU), split or duplicate names to fill-in the given and surname fields, or use honorific titles. Regardless of the option chosen, it may not be accepted by the government receiving the API message and could trigger a notification of data quality concerns to the airline and an ensuing fine.

In order to limit airlines and governments current varying practices, the IATA CAWG recommends that when a passport misses a surname or given name field, the airline should support the code FNU for the given name in both the PNR and in the API message.