Whether the revised assessment could be annulled because the original discretionary assessment was allegedly void or unlawful.
No. The revision was limited to the portion affected by the revision ground, namely the inter-cantonal allocation of self-employed income; any challenge to the discretionary assessment itself had to be brought by ordinary remedies and could not be revived through revision.
Tax law allows reopening only on enumerated grounds. The correction concerned only income that had to be attributed to Zurich under the ban on inter-cantonal double taxation. Missed ordinary remedies cannot be cured by claiming revision or nullity.