Scope of scrutiny limited to reported third-party mismatches; broader probes require prior written approval and monitoring. Instruction limits scrutiny in cases selected under Computer Aided Scrutiny Selection for AIR/CIB/26AS mismatches to verification of the specific point(s) forming the basis of selection; questionnaires and notices should be confined to those aspects, proceedings completed expeditiously, and broader comprehensive scrutiny permitted only where potential income escapement crosses prescribed monetary thresholds with prior written approval and subsequent monitoring.