PRCT_HEAD_COM 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 "Communication Fields from Pricing Header" 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_PRCT_HEAD_COM TYPE PRCT_HEAD_COM.
The PRCT_HEAD_COM table consists of various fields, each holding specific information or linking keys about Communication Fields from Pricing Header data available in SAP. These include R3_KNUMV (Number of Document Condition in R/3), KAPPL (Application), KALSM (Pricing Procedure), VERSION (Version Number of Pricing Procedure)... 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. .