Disclosure of assessee information: tax authorities may share taxpayer data with other tax or exchange bodies when necessary for functions. Section 138 permits the Board or a specified income-tax authority to furnish information received by income-tax authorities to officers, authorities or bodies under tax, duty, cess or foreign exchange laws, or other specified authorities when necessary to enable them to perform their functions; a designated Chief/Principal Commissioner may, if satisfied it is in the public interest, furnish requested information to applicants with a final administrative decision; the Central Government may by notification restrict furnishing of information or documents for specified classes of assessees or authorities.