Reference to Commissioner for impermissible avoidance arrangements mandates notice, hearing rights, and possible Approving Panel directions. A procedure requires an Assessing Officer who considers Chapter X-A applicable to refer the matter to the Commissioner. The Commissioner, if satisfied, must give the assessee notice and an opportunity to object; absent objections he may issue binding directions declaring an arrangement an impermissible avoidance arrangement. If objections are not accepted, the Commissioner refers the case to an Approving Panel, which may direct declaration, specify applicable previous years, call for inquiries or documents, and issue binding directions that Assessing Officers and Commissioners must follow; Panel decisions are by majority and subject to a six-month limitation.