Converting a GDS name list into a longsell reads infant passengers correctly, including infants entered without a date of birth.
Frequent flyer numbers are easier to add too. When you type a number in manually, the associated flight is optional, the same as when you pick a saved number from the dropdown, and the program name is optional as well.
This helps agents who build trips from a PNR rather than from the client list, and anyone adding loyalty numbers while a booking is in motion.