Finality of tax assessments: reward processing follows assessment or settlement finality, or upon informant's written undertaking. Processing of a final reward is permitted where assessments or appeals have attained finality by lapse of remedies or time, where a settlement order has attained finality after challenge or rectification avenues have lapsed, or where an informant requests award based on undisputed additional taxes and provides an unconditional written undertaking before the concerned tax official that he will make no further claim in the relevant group of cases.