RFCAT_FIELDS 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 "Field Catalog - Structure with Field Status Information" 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_RFCAT_FIELDS TYPE RFCAT_FIELDS.
The RFCAT_FIELDS table consists of various fields, each holding specific information or linking keys about Field Catalog - Structure with Field Status Information data available in SAP. These include FIELDSTATUS (Field Status), STATUS_HIDE_AVLB (Field Status 'Hidden' is Available), STATUS_DISP_AVLB (Display Field Status is Available), STATUS_EDIT_AVLB (Field Status 'Ready for Input' is Available)... 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. .