Confidentiality of taxpayer information: disclosure barred without consent; limited access permitted and class reporting allowed for public interest. Bar on disclosure prohibits publishing particulars from any individual's return supplied for statutory purposes in a manner that identifies the person without prior written consent; confidentiality restricts access to those engaged in collection, compilation or computerization for the statute's purposes and permits inspection only for prosecution; the Commissioner may permit publication of aggregated information about a class of dealers or transactions when desirable in the public interest.