FTPRN is a standard SAP Structure so does not store data like a database table does. It can be used to define the fields of other actual tables or to process "Fields in the Communication/Printing area" Information within sap ABAP programs. This is done by declaring abap internal tables, work areas or database tables based on this Structure. These can then be used to store and process the required data appropriately. i.e. DATA: wa_FTPRN TYPE FTPRN.
The FTPRN table consists of various fields, each holding specific information or linking keys about Fields in the Communication/Printing area data available in SAP. These include PB_PRFE (Error Processing for Printing), PB_PRWE (Repeat Processing for Printing), PB_PRSO (Special Case Processing for Printing), PB_COER (Communication First Processing)... See below for full list along with technical details, documentation, text table, check tables, foreign key relationships, conversion routines, relevant tcodes and example ABAP select code etc. .