Actually NSFX sn NPFX are NOT the correct way to format the data in the GEDCOM according to the 5.5 spec:

The NPFX, GIVN, NICK, SPFX, SURN, and NSFX tags are provided optionally for systems that cannot operate effectively with less structured information. For current future compatibility, all systems must construct their names based on the structure. Those using the optional name pieces should assume that few systems will process them, and most will not provide the name pieces.