FCOM_S_COSS_KEY_FIELDS_SPECIAL 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 "Key Fields Specific for Table COSS" 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_FCOM_S_COSS_KEY_FIELDS_SPECIAL TYPE FCOM_S_COSS_KEY_FIELDS_SPECIAL.
The FCOM_S_COSS_KEY_FIELDS_SPECIAL table consists of various fields, each holding specific information or linking keys about Key Fields Specific for Table COSS data available in SAP. These include USPOB (Source Object (Cost Center/Activity 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. .