§ 3003. Content of tax due, deficiency, and other notices. Any first letter of proposed deficiency or determination (commonly called a thirty day letter) issued by the commissioner, and any notice and demand, notice of deficiency or notice of determination which is issued by the commissioner, which is manually initiated and which is the first such letter or notice issued to the taxpayer with respect to the subject matter of such notice, shall describe the basis for (such as the statutory or regulatory law, or judicial or tax appeals tribunal decision), and identify the amounts (if any) of the tax due. An inadequate description under this section shall not invalidate such letter or notice.