The mzPAF specification is heavily based on the formatting used in the NIST MSP format and the SpectraST sptxt format. These precursor formats were quite similar, but not exactly the same, and were never fully documented. NIST MSP annotations have undergone small changes over the years. Those annotation formats are based on the original nomenclature proposals published by Roepstorff and Fohlman, which was further refined by Biemann. Participation from NIST and SpectraST developers and many others have led the development of this unified standard.