Notice deemed served: cooperation or appearance bars objections to non-service, late service or improper service. A new provision deems notices under the Income-tax Act as duly served where the assessee has appeared in proceedings or cooperated in inquiries relating to assessment or reassessment, and precludes objections that the notice was not served, not served in time, or served in an improper manner, subject to an exception where the assessee raised such objection before completion of the assessment or reassessment.