Continuation of recovery proceedings: enhanced or reduced tax adjustments permit continuation without fresh demand notice. Where a notice of demand for Government dues has been served and an appeal, revision or other proceeding is pending, an enhancement of dues requires the Commissioner to serve a notice only for the increased amount while recovery proceedings based on the earlier demand may continue without a fresh notice from the stage they had reached; where dues are reduced, no fresh notice is required, the Commissioner must intimate the reduction to the taxpayer and the recovery authority, and recovery for the reduced amount may continue from the same procedural stage.