RCNCOMP 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 "Component data for the planning board" 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_RCNCOMP TYPE RCNCOMP.
The RCNCOMP table consists of various fields, each holding specific information or linking keys about Component data for the planning board data available in SAP. These include RSPOS (Item Number of Reservation/Dependent Requirement), RSART (Record type), BANFN (Purchase Requisition Number), BNFPO (Item Number of Purchase Requisition)... 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. .