§297
Section 297 — Certain interests and penalties not to be levied or imposed
In plain terms: This section says interest under sections 423, 424 or 425 and penalty under section 439 are not levied on undisclosed income assessed for a search-case block period.
Interest under sections 423, 424 or 425 or penalty under section 439 shall not be levied or imposed upon the assessee for the undisclosed income assessed or reassessed for the block period.