Home › CFR › Title 26 › Part 5f26 CFR Part 5f — Temporary Income Tax Regulations Under the Tax Equity and Fiscal Responsibility Act of 1982§ 5f.103-1— Obligations issued after December 31, 1982, required to be in registered form.§ 5f.163-1— Denial of interest deduction on certain obligations issued after December 31, 1982, unless issued in registered form.