APPL_SUB 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 "Subscreens for an application for tab page settings" 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_APPL_SUB TYPE APPL_SUB.
The APPL_SUB table consists of various fields, each holding specific information or linking keys about Subscreens for an application for tab page settings data available in SAP. These include REPID (ABAP Program Name), DYNNR (Number of the following screen), TEXT (Short description of the detail screen), MARK (Checkbox)... 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. .
