CIF_PPMKEY 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 "External PPM Key (Production Version)" 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_CIF_PPMKEY TYPE CIF_PPMKEY.
The CIF_PPMKEY table consists of various fields, each holding specific information or linking keys about External PPM Key (Production Version) data available in SAP. These include MATNR (Material Number), WERKS (Plant), VERID (Production Version), PLNTY (Task List Type)... 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. .