This controls use of the base ScreenDef IncludeFilter in the case that no field filtering is desired. Since the UIScreen IncludeFilter will only override the base ScreenDef IncludeFilter if it is non-blank, this property is needed in the case where there is a base ScreenDef filter but no filters at all are wanted.
When this is set false, no filter will be used when generating the web page.
