(b)shall make such amendment for rectifying any such mistake which has been brought to its notice by the assessee, and where the authority concerned is the [* * *] [ Certain words omitted by Act 21 of 1998, Section 65 (w.e.f. 1.10.1998).] [Commissioner (Appeals)] [ Inserted by Act 29 of 1977, Section 29 (w.e.f. 10.7.1978).], by the [Assessing Officer] [ Substituted by Act 4 of 1988, Section 2, for " Income-tax Officer" (w.e.f. 1.4.1988).] also.