Pictured in Figure 3.11.10-22 is an example of a taxpayer letter overlaid by an example of a Form 3244A, Payment Posting Voucher - Examination, where an edited Primary TC 640 (Advance Payment of Determined Deficiency or Underreporter Proposal) is entered when the Primary TC was not specified. The taxpayer letter (a short note) indicates that the payment is for estimated tax payments which are processed with TC 640. A bubble box marked Route to Correspondence is on the right margin of the letter to indicate that the letter must be sent to Correspondence (i.e., Taxpayer Relations).