Impermissible avoidance arrangement: reference to Approving Panel initiates formal panel review under the statutory referral procedure. Once the commissioner, after considering the assessee's explanation and relevant facts, is satisfied that an arrangement is an impermissible avoidance arrangement, that satisfaction must be recorded in the prescribed satisfaction form and a formal reference made to the Approving Panel by written request identifying the assessee and the earlier referral from the Assessing Officer.