Optional. The ShowField attribute can be set to the field name to be displayed. By default, a hyperlinked text from the Title ...

Optional. The ShowField attribute can be set to the field name to be displayed. By default, a hyperlinked text from the Title field of the record in the external list is displayed. But the ShowField attribute can be used to override that and display another field from the external list. The following data types are allowed as targets of a ShowField attribute: Text, Choice, and Counter. For a Lookup field, this parameter must be set to the internal field name; setting it to the display name does not raise an error, but breaks the field.