Regulation of appeals by tax board permits withholding appeals under set limits without creating acquiescence. Board authority may issue orders, instructions or directions fixing monetary limits to regulate filing of appeals or applications for reference by income tax authorities. Non filing pursuant to those limits does not bar the authority from filing in other cases nor permit an assessee to claim acquiescence. Appellate tribunals or courts must regard the Board's instructions and the circumstances of filing or non filing, and prior monetary limit orders are deemed issued under that regulatory power.