APPCORE.PLL:
Is the collection of Procedures, Functions and Packages used to define Menus and Tool Bars.
CUSTOM.pll
Is used to add extensions to Oracle's form Functionality. Some of the common scenario where CUSTOM.pll can be used are:-
Enabling/Disabling the fields
Changing the List of Values in a LOV field at runtime.
Defaulting values
Additional record level validations
Navigation to other screens.
- Enabling Special Menu