Sanction requirement for reassessment notices tightened: senior officers must be satisfied on recorded reasons before issuing notice. Amendment revises the sanction regime for issuance of reassessment notices: notices issued after the four year limitation period require satisfaction by senior tax commissioners on the Assessing Officer's recorded reasons that the case is fit, while notices in other cases proposed by officers below Joint Commissioner require prior satisfaction by a Joint Commissioner on the recorded reasons; the sanctioning authority need not itself issue the notice.