Definition of case in settlement proceedings clarifies when assessment proceedings commence and conclude for settlement eligibility. Defines key terms for Chapter VA settlement of cases: 'case' covers proceedings for assessment or reassessment pending before an Assessing Officer when an application under section 22C(1) is made, with an Explanation specifying when different assessment or reassessment proceedings are deemed to commence and conclude. It also defines institutional roles-Bench, Chairman, Member (including Chairman and Vice Chairman), Vice Chairman (including the senior Member of a Bench)-and identifies the 'wealth-tax authority' as the income tax authority treated as such; amendment history modifies these temporal and definitional rules.