Confidentiality of tax returns bars publication or use without consent, permitting limited access for prosecution or statistics. Confidentiality of taxpayer information prohibits publication or use of individual return data without the prior written consent of the concerned person or authorised representative, and such information may not be used in proceedings under the Act; access is limited to those engaged in statistical collection, compilation, or computerization for the Act, except that limited access may be permitted for prosecution, and the Commissioner may authorize publication of aggregated class-level information in the public interest.