In Microsoft Dynamics 365 Finance and Operations, extensions are the mandatory method for modifying standard objects like the CashDisc table, as overlayering is no longer supported for base packages. To add a new data element, you create a field within the table extension. To ensure this field appears automatically on forms that utilize standard UI patterns, it must be added to an existing field group (e.g., Identification or Administration). Finally, to synchronize these metadata changes and ensure the form's layout recognizes the updated field group membership, developers must Restore the form design in the development environment.

Microsoft Learn (Official Vendor Documentation): "Extensibility home page" and "Customization: Overlayering and extensions." This documentation specifies that extensions are the only supported way to modify standard objects in the Application Object Tree (AOT).

Microsoft Learn: "Modify a standard form by using an extension." This section details adding fields to field groups within table extensions to affect form layouts.

Microsoft Learn: "Table Extension - Add Fields." Specifically covers the process of adding a field to a table and then referencing that field within a field group to maintain UI consistency.

Microsoft Dynamics 365 F&O Development Standards: Guidelines on using the "Restore" command on form design nodes to refresh metadata from the underlying data source and field group definitions.