The purpose of PAPI systems is (1) to represent student records, and (2) to communicate this information with other applications.
PAPI specifies data interchange formats, i.e.,a representation of information in some encoding.
The PAPI specification is not a protocol, but could be used as a basis for a data communications protocol (other information, flow, and processing would be described to fully define the protocol).
The PAPI specification is not a database format (PAPI alone is inefficient for database organization), but PAPI could be used to import data to and/or export data from a database.