This drop down combo is visible when the "Method" buttons are
(Implode) and (Implode) and the action is
equal to where-used replacement of a component.
It refers to the number of the component that replaces the
component in the Component To Be Replaced field.
It is populated with all Part Numbers, Descriptions, Source,
Fixed Account and Serial/Lot Control from the Part Master table.
The number of characters to be entered before the list is shown
is governed by the value of "populate length" (mandatory).