SMI_S_DM_HEADER 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 "SMI Header Data Structure" 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_SMI_S_DM_HEADER TYPE SMI_S_DM_HEADER.
The SMI_S_DM_HEADER table consists of various fields, each holding specific information or linking keys about SMI Header Data Structure data available in SAP. These include MESSAGE_CREATIONDT (DateTime), MESSAGE_RECEIVEDDT (DateTime), MESSAGE_SCHEMEAGENCY_ID (Scheme Agency ID), MESSAGE_SENDERPARTY_INTID (Internal ID)... 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. .